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GEOLOGICAL SURVEY OF GEORGIA 

W. S. YEATES, State Ceologist 



BULLETIN No. 2 
A 

Preliminary Report 

on the 

Corundum 

DEPOSITS 



OF 



GEORGIA 

BY 

FRANCIS P. KING 

Assistant Geologist 



1894 

QEO. W. HARRISON, State Printer 

Atlanta, Ga. 



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GEOLOGICAL SURVEY OF GEORGIA 

W. S. YEATES, State Geologist 



BULLETIN No, 2 



A PRELIMINARY REPORT 



Corundum Deposits 



or 



GEORGIA 



FRANCIS P. KINO 
Assistant Geologist 



1894 



Atlanta, Ga. 

The Franklin Printing and Publishing Co. 

Geo. W. Harrison State Printer, Manager 



Monograph 






THE ADVISORY BOARD 

Of the Geological Survey of Georgia. 



(Ex-Officio). 

His Excellency, W. J. NORTHEN, Governor of Georgia, 

President of the Board. 

Hon. R. T. NESBITT, ...... Commissioner of Agriculture. 

Hon. S. D. BRADWELL, . . . Commissioner of Public Schools. 

Hon. R. U. HARDEMAN, State Treasurer. 

Hon. W. A. WRIGHT, Comptroller-General. 

Hon. J. M. TERRELL, Attorney-General. 



5 



CONTENTS 



Page. 

LETTER OF TRANSMITTAL 5 

PREFACE 7 

CHAPTER I. 

HISTORY OF CORUNDUM 9 

Early History 9 

History of Corundum in the Eastern Hemisphere . . . . 11 

History of Corundum in America 13 

Nomenclature of Corundum . 21 

CHAPTER II. 

VARIETIES OF CORUNDUM 23 

Introductory Remarks 23 

Sapphire 24 

Corundum 26 

Emery 28 

Physical Properties 29 

Artificial Production of Corundum 34 

CHAPTER III. 

ALTERATIONS AND ASSOCIATE MINERALS OF CORUN- 
DUM 36 

General Observations 36 

Oxides of Silicon 37 

Hydrous Oxides of Aluminum 37 

Anhydrous Oxides of Other Metals 41 

Anhydrous Silicates 42 

Hydrous Silicates 49 

I. Micas 49 

II. Clintonites 52 

III. Chlorites 52 

IV. Vermiculites 53 

V. Serpentine and Talc 56 

Phosphates 57 

CHAPTER IV. 

GEOLOGY OF THE CRYSTALLINE BELT 58 

Introduction , 58 

Map of Georgia 58 



CONTENTS. 

Page. 

Topography of the Crystalline Belt 60 

Structure and Physiography of the Crystalline Belt, and 

its Evolution 61 

Age of the Crystalline Belt 67 

Geology of the Holo-crystalline Area 71 

CHAPTER V. 

DISTRIBUTION OF CORUNDUM IN GEORGIA 73 

Position of the Corundum-bearing Formations 73 

Geological Relations of the Corundum-bearing Formations 74 

Corundum Veins 75 

Varieties of Corundum Found 76 

Description of Localities . 76 

Origin of Georgia Corundum 106 

CHAPTER VI. 

ECONOMICS - . . 109 

History of Corundum Mining in Georgia 109 

Value of the Georgia Deposits 109 

Preparation and Manufacture of Corundum no 

Statistics 112 

Hints to Prospectors 114 

CHAPTER VII. 

AMERICAN LITERATURE ON CORUNDUM 116 

CHAPTER VIII. 

(Supplementary.) 

NATURAL AND ARTIFICIAL ABRASIVES 119 

Natural Abrasives 119 

Pumice 119 

Infusorial Earth 119 

Tripoli 120 

Buhrstones 121 

Grindstones 122 

Oilstones and Whetstones 124 

Artificial Abrasives 126 

Crushed Steel 126 

Carborundum • 127 



State of Georgia, Geological Survey, 

Atlanta, Sept. 15, 1894. 

To His Excellency, W. J. Northen, Governor, and President of the 
Advisory Board of the Geological Survey of Georgia, 

Sir: — I have the honor to transmit, herewith, the report of Mr. 
Francis P. King, Assistant Geologist, on the Corundum Deposits 
of Georgia. 

The importance of corundum in the arts, and the high price it 
commands, should make this report of special interest, Georgia 
ranking second in the Union, in its production. It is hoped, that 
this publication will act as a stimulus to the discovery, in Georgia, 
of other deposits of this valuable mineral. 

Like the report on the " Marbles of Georgia," this bulletin is 
preliminary to a final general report, in which it will be incorpo- 
rated, with such additional information, as we may be able to get, 
bringing the subject up to date. 

Very respectfully yours, 

W. S. Yeates, 
State Geologist. 



PREFACE 



The subject-matter of this report, it is hoped, is of a nature, to 
fill a want, continually expressed to the Survey, by citizens inter- 
ested in this special line of work. In its presentation, with this 
expression of need in mind, technicalities have been avoided, in so 
far as scientific treatment would permit, and many features have 
been elaborated; in other words, an attempt has been made to har- 
monize scientific accuracy and practical usefulness, by introducing 
such material, and presenting all, in such a manner, that the report 
will be both serviceable and easily intelligible to the average reader. 

Several of the chemical analyses, which appear in this volume, 
were made in the laboratory of the Survey by Dr. William H. 
Emerson, Professor of Chemistry in the Georgia School of Tech- 
nology. His careful and admirable work speaks for itself. 

In conclusion, I desire to express my obligations to the State 
Geologist for many favors; also, to many citizens of the State for 
their assistance and hospitality. Space will not permit the enumer- 
ation of all these; but I would mention in particular, Mr. Thomas 
S. Bean of Clarkesville, Mrs. H. A. Burdick, Manager of the Lau- 
rel Creek Corundum Mine, Pine Mountain, Rabun Co., Ga., Mr. 
Corn of Visage, Mr. William R. McConnell and Mr. O. C. Wyly of 
Hiawassee, Mr. John McConnell of Gainesville, Mr. R.J. Cook of 
Track Rock, Prof. Leon P. Smith of La Grange, and Dr. E. D. 
Little of Sheltonville. 

Sept. 15, 1894. F. P. K. 




33 



SCALE OF N 
5 10 



LEGEND 



SEDIMENTARY 



EOCENE 



CRETACEOUS 



CARBONIFEROUS 



DEVONIAN 



SILURIAN 



CAMBRIAN 



ALGONKIAN 



CRYSTALLINE 



CORUNDUM 




20 



xTi5 

IDEOLOGICAL SURVEYOR GEORGIA 

W. S. YE ATE. S, State Geologist 

TO ACCOMPANY A PRELIMINARY REPORT ON THE 
CORUNDUM DEPOSITS OF GEORGIA 

BY FRANCIS P KING, ASST GEOLOGIST 

1894 i 



&z* 



THE 

Corundum Deposits of Georgia 



CHAPTER I. 



HISTORY OF CORUNDUM. 

Early History. 

History of Corundum in the Eastern Hemisphere. 
History of Corundum in America. 
Nomenclature of Corundum. 



EARLY HISTORY. 

Little is known of the early history of corundum, although spec- 
ulations are rife among writers, dwelling on the handiwork of the 
ancients. Thus, the dexterity of the Egyptians in stone-carving, 
several thousand years before the Christian era, as shown by their 
monuments, suggests to these writers, that the work was accom- 
plished by means of some very hard abrasive, such as corundum. 
For example, Mr. Wilkinson, the English antiquarian, whose scien- 
tific researches in Egyptian history are well known, writes: — " It is 
in no wise improbable, that they were familiar with the use of emery, 
at the time, when that substance, which is met with in the islands 
of the Archipelago, was accessible to them; and, if this be ad- 
mitted, we can explain the perfection and admirable delicacy of 
their hieroglyphics upon the monuments of granite and basalt." 1 

1 Manners and Customs of the Ancient Egyptians, by "Wilkinson. 1st Edition, 
Vol. III., pp. 250-257. 



10 HISTORY OF CORUNDUM. 

More authentic knowledge of the ancients' acquaintance with 
corundum is confined to the gems of corundum. That they appre- 
ciated their value, and sought them as eagerly as we, may be fully 
understood, when we learn that they regarded the ruby as the very 
type of all, that is most precious in the natural world. Moreover, 
we know that the desire to possess, led men to seek them in foreign 
lands in the time of Solomon. In the Bible, we find the gems of 
corundum mentioned quite frequently. In Exodus, chapter xxviii, 
we learn that the breastplate, which God commanded the people to 
make for Aaron, was to contain, among the twelve precious stones, 
a carbuncle 2 and a sapphire. Ezekiel tells us, that the king of Tyre 
had as a covering, among other precious stones, both the ruby and 
the sapphire. John, in Revelations, describes the foundations of 
the walls of the heavenly city, as being "garnished with all manner 
of precious stones," among which were the gems of corundum. 

The early Greek writers teem with descriptions and allusions to 
these gems. From these, we learn that they engraved and cut them, 
long before the Christian era, and that, in Egypt, they were worked 
as Scariabean gems. From such writers, also, we learn that the 
ancients believed the occurrence of precious stones to be confined 
to certain climates, and "were wont to ascribe the preeminence of 
certain regions to evaporation from the earth, in which precious 
stones are found, an evaporation obviously more intense in tropical 
countries. It was a supposition, pardonably fanciful, that the sun- 
burnt tropics were more favorable to the blossoms of the organic 
world, than the dark skies of the north." 3 Naturally, to stones so 
rare and possessed of such wonderful beauty, the ancients attached 
miraculous power, increasing inestimably their preciousness. It is 
unnecessar}', perhaps, to say that these ancient superstitions have 
not been entirely effaced; and to-day people may be found, who 
still give credence to these ancient beliefs. This superstition, partic- 
ularly, makes the ancient writers' mention of them so fanciful and ob- 
scure, that we are often left in doubt, as to real name of the stones. 

2 There is little doubt among authorities, hut that the Greek word anthrax, here trans- 
lated carbuncle, is the corundum gem, ruby. 

3 Edwin W. Streeter; Precious Stones and Gems ; 3rd Edition, p. 7. 



HISTOR Y OF COR UND UM. 1 1 

We find, nevertheless, certain writings of the Greeks, as far 
back as the sixth century B. C, which indicate a considerable 
knowledge of the physical properties of these gems. In the fifth 
century B. C, the writings of the Greeks begin to show special 
acumen in the description of minerals, as seen in the writings of 
Aristotle and his pupil, Theophrastus, the latter writing an excel- 
lent treatise on mineralogy. 

Roman succession to the treasure-field marked an increase ira 
mineralogical knowledge and a fuller acquaintance with the char- 
acteristics of these gems. Pliny, especially, seems to be well in- 
formed, as to where the precious ruby and sapphire occur, and his 
descriptions of them are sharp and observant. Passing into the 
Christian era, writers on mineralogy increase, and the subject is 
developed into a science; but the superstitious legend of the past 
continued more or less gospel, and precious stones were still wor- 
shipped, worn as amulets etc. The twelve apostles were repre- 
sented by gems called Apostle Stones; and thus the beautiful blue 
sapphire became emblematic of the heavenly faith of Andrew. 

HISTORY OF CORUNDUM IN THE EASTERN HEMISPHERE. 

The first known occurrence of corundum is the emery of the 
Grecian Islands. It is supposed that the early Egyptians obtained 
emery from this point, and made considerable use of it in the arts. 
Indeed, up to the time of the discovery of emery in Asia Minor, in 
1847, by Dr. J. Lawrence Smith, of Louisville, Ky., it was exported 
exclusively from these islands, principally from the Island of Naxos 
in the Grecian Archipelago. The owners of these mines completely 
controlled the price of emery, and were selling their product at 
from forty to fifty dollars per ton. At the time Dr. Smith, in the 
employ of the Turkish Government, made his important discovery, 
these mines had been purchased from the Greek Government, by 
an English merchant, and the price had advanced to one hundred 
and forty dollars per ton. This new discovery reduced the price, 
writes Dr. Smith in 1850, to fifty and seventy dollars a ton accord- 
ing to quality. The importance of this discovery was not ap- 
propriated completely by the Turkish Government. Corundum, 



12 HISTORY OF CORUNDUM. 

formerly of little interest, except in the arts and as a gem, took 
on a new importance under the able researches of Dr. Smith. Pre- 
vious to this time, it was known to occur, only in a few localities, 
while, as to the method of its occurrence, that is, its geological re- 
lation, very little was known. In 1850, Dr. Smith presented two 
papers before the Academy of Science of Paris — to quote his 
own words 1 — "in which the subject was thoroughly discussed, and, I 
might say, almost exhausted." If Dr. Smith did not exhaust the sub- 
ject, he at least developed such important facts, in regard to its geo- 
logical relations and associate minerals, as to urge investigation and 
the consequent discovery of many new localities, both in the Old 
and the New World. 

The occurrence of corundum in the Eastern Hemisphere accord- 
ing to Dana is as follows: — "The best rubies come from the mines 
in Upper Burma, north of Mandalay, in an area covering 25 to 29 
square miles, of which Magok is the center. Also found in the 
marble hills of Sagyin, 16 miles north of Mandalay. The rubies 
occur in situ in crystalline limestone ; also in the soil of the hillsides, 
and in gem-bearing gravel. All the crystallized varieties of the 
species occur here; the spinel-ruby is an associate. A ruby weigh- 
ing 304 carats is said to have been found here in 1890. Rubies 
and sapphires have also been reported from other localities, and the 
massive varieties are common, especially in the crystalline rocks of 
southern India. Ruby mines have also been worked at Jagdalak, 
32 miles east of Kabul, Afghanistan. Some fine sapphires were 
obtained in 1882 from the Zanskar range of the Kashmir Himalayas, 
near the village Machel in Padar; and, since then, mining has been 
carried on there, with some success. Blue sapphires are brought 
from Ceylon, often as rolled pebbles, but also, as well preserved 
crystals. Corundum occurs in the Carnatic, on the Malabar coast, 
on the Chantibun hills in Siam, and elsewhere in the East Indies; also 
near Canton, China. At St. Gothard, it occurs of a red or blue 
tinge in dolomite, and near Mozzo in Piedmont, in white compact 
feldspar. Adamantine spar is met with, in large, coarse, hexagonal 
pyramids in Gellivara, Sweden. 

1 Dr. J. Lawrence Smith; Emery Mine of Chester; Scientific Kesearches, p. 42. 



HISTORY OF CORUNDUM. 1 3 

Emery is found in large bowlders at Naxos, Nicaria and Samos 
of the Grecian islands; also in Asia Minor, 12 miles east of Ephesus, 
near Gumuch-dagh, where it was discovered in situ by Dr. J. 
Lawrence Smith, associated with margarite, chloritoid, pyrite, cal- 
cite etc.; and, also, at Kulah, Adulah and Manser, the last, 24 
miles north of Smyrna; also, with the nacrite (?) of Cumberland, 
England. Other localities are in Bohemia, near Petscha, in the 
Ural, near Ekaterinburg, and in the Ilmen mountains, not far from 
Miask; in the gold-washings northeast of Zlatoust, as small crys- 
tals (called soimonite after Senator Soimonov) inbarsovite. Corun- 
dum, sapphires and, less often, rubies occur in rolled pebbles, in the 
diamond gravels on the Cudgegong river, at Mudgee and other 
points in New South Wales." 1 

HISTORY OF CORUNDUM IN NORTH AMERICA. 
GENERAL REMARKS. 

Authentic history of corundum in America dates back to the 
early part of this century. Whether or not the Indians knew of its 
presence, and made use of it, is simply a matter of conjecture. 
Their presence in the neighborhood of the occurrences in Georgia 
is everywhere apparent. This is evidenced in the old carvings on 
rocks, and the presence of incomplete or broken utensils. The soap- 
stone of the formation, because of its ease in working, was especially 
attractive to them for the making of pipes, vessels etc. In the road 
a few hundred yards above the works at Track Rock Mine, Union 
county, Ga., there are several slabs, one of which is remarka- 
bly well preserved, bearing most curious hieroglyphics deeply cut into 
the rock. Some of these can be made out, as tracks of animals, 
while the others only the imaginative are permitted to interpret. 2 

There can be but little doubt, however, that, during their 
presence in these localities, the glistening beauty of the blue and 
red fragments of corundum, scattered through the soil, attracted 
the watchful eye of the red man, and was soon lovingly adapted to 
savage finery. 

1 Dana; System of Mineralogy — 6th Edition; p.p. 212-213. 

2 See figure 1. 



H 



HISTORY OF CORUNDUM. 



KIG I. 



















Track Eock, Union County, Georgia. 



The first authentic date to be found, of the discovery of corun- 
dum in North America is 1845; it was then discovered in the town- 
ship of Newlin, Chester county, Pa. Following the discovery of 
emery at Chester, Mass., however, in 1864, anc ^ tne knowledge of 
the subject, disseminated by Dr. J. Lawrence Smith, Professor C. U. 
Shepard and Professor C. T. Jackson, explorers began traversing 
the eastern crystalline belt of the United States from Virginia to 
Alabama. The result of their work confirmed the prophesies of 
the mineralogists; corundum was found all along the line. Mines 
were opened up in several States, explorers entered the field, and 
new localities have been continually added to the list, up to the 
time of the present writing. 

Prominent among the early explorers may be mentioned Rev. 
C. D. Smith and Colonel C. W. Jencks, of North Carolina, and Dr. 
H. S. Lucas, of Massachusetts. To these indefatigable workers 
is undoubtedly due the most credit, for the development of the 
corundum resources of North Carolina and Georgia. 



HISTOR Y OF COR UND UM. 1 5 

Canada. — Little is known of the presence of Corundum in 
Canada. I am informed by Dr. Adams, of McGill College, Mon- 
treal, that it is known to occur only in one locality. The record of 
this, in the survey report for 1863, is as follows: — " Corundum has 
been observed in the second lot of the 9th range of Burgess, 1 
and in the immediate vicinity of a deposit of copper pyrites. 
Here, in contact with the crystalline limestone, occurs a rock made 
up of feldspar, quartz, calcite, silvery-white mica and sphene. 
Disseminated throughout this aggregate were small grains of a 
mineral, whose color varies from light rose-red to sapphire-blue, 
while its hardness, which was greater than that of topaz, showed 
the mineral to be corundum . Small crystals of light-blue corun- 
dum have been found elsewhere in the limestone of the vicinity." 2 

Maine. — Dana says, that a few crystals of corundum have been 
found at Greenwood in a mica-schist, with beryl, zircon and lepido- 
lite. With this exception, no record of its occurrence in the State 
can be found. Dr. W. S. Bayley, Professor of Mineralogy and 
Geology at Colby University, writes that the locality mentioned by 
Dana is unknown to the collectors. 

Massachusetts. — Professor C. T. Jackson, on October 22nd, 
1863, while surveying an iron mine at Chester, Mass., discovered 
some veins of margarite, and, from this, " ventured to predict the 
occurrence of emery." 3 About a year later, he met Dr. Lucas, 
one of the owners of the mine, and again called his attention to 
this discovery. " The next day after his return to Chester, he 
(Dr. Lucas) found the emery, a big vein nearly six feet wide, 
which had been mistaken by him for iron ore, it being very mag- 
netic." 3 This discovery marks the opening of the industry in 
America. Mills were erected at Chester, Mass., for the prepara- 
tion of this mineral for the market ; but the emery, mined some- 
time, was finally found to be too soft for the trade, and has since 
been abandoned. Later, corundum was mined there. 

Professor Shepard found the vein to have an extent of about 

1 A township and a province of Ontario. 

2 Keport of Geological Survey of Canada for 1863, page 499. 

3 Scientific Kesearches ; J. Lawrence Smith, page 44. 



1 6 HISTORY OF CORUNDUM. 

four miles, and an average width of four feet. It extends through 
a great gneiss formation, flanked on the east by a mica-slate. Be- 
tween the mica-slate and the eastern gneiss wall, talcose-slates in- 
trude, averaging from twenty to one hundred feet in thickness. 
No corundum, emery or magnetic particles have thus far been de- 
tected as constituents of the gneiss; but particles of these minerals 
are scattered throughout the talcose formation. The minerals, 
associated with the emery vein, are corundum, diaspore, ripidolite, 
margarite etc. 

Connecticut. — Professor Greorge J. Brush has in his collection 
two specimens of corundum, which were found in this State in 
1870. This is approximately the date of the discovery of corun- 
dum in Connecticut. Dana reports it from near Litchfield, and at 
Norwich, with sillimanite, rare. It also occurs at Newton, in Fair- 
field county. 

Professor S. L. Penfield writes me, that the crystals are light 
pink, presenting the simple combination of short hexagonal prisms 
of the second order with the basal plane. No work has been done 
to open up a vein ; consequently, the nature of its occurrence is 
unknown. Professor Penfield thinks it occurs in the crystalline 
schists, since the crystals of corundum are found embedded in blue 
kyanite. 

New York. — Corundum was discovered, very early, in this 
State. It has been found at Warwick and Amity, Orange county? 
also in Cortlandt Township, Westchester county. The latter 
locality was described by Professor George H. Williams, in his in- 
teresting papers on the "Cortlandt Series." Westchester county, 
up to last year, when the mining company assigned, was one of 
the sources of supply to the United States. 

New Jersey. — The State Geologist reports, that it was probably 
first found at Vernon, date unknown. A prolongation of the New 
York dolomitic limestone, bearing corundum, at Franklin, Newton 
and Vernon, furnish isolated pockets of blue and red corundum. In 
Sussex county, it occurs in the gneissoid rock. No economic work 
on corundum has been done in this State. 



HISTOR Y OF COR UND UM. 1 7 

Maryland. — Tyson reports the occurrence of corundum near 
White Hall. Considerable work had been done here on magnetic 
iron and copper ore, in the magnesian belt, previous to the civil 
war; and, since then, several geologists have examined the locality 
for corundum, but without success. 

Pennsylvania. — In i845 some large masses of corundum were 
found on the surface; and later it was mined in Newlin township, 
Chester county. This is probably the first discovery of corundum 
in Pennsylvania. A paper on the minerals in the vicinity of Phila- 
delphia, by Dr. Isaac Lea, in the proceedings of the Academy of 
Natural Sciences, 1818, does not mention corundum, although the 
writer had explored, to a great extent, Chester and Delaware coun- 
ties. Following the discovery of corundum in 1845 at Newlin, it 
was found commencing near Blue Hill, in Upper Providence Town- 
ship, and extending for about five miles to near Rockdale, Middletown 
Township, Delaware county, and again appearing near Unionville, 
in Newlin Township, Chester county. Mr. T. D. Rand, of Phila- 
delphia, who has kindly supplied me with information on the his- 
tory of corundum in Pennsylvania, says that a locality in Lehigh 
county shows no indication of serpentine, as at the other localities, but 
that the corundum occurs chiefly in large, loose crystals in a gran- 
itic or syenitic rock. The deposit in Chester county, at the time Dr. 
Genth wrote Volume B of the Pennsylvania Geological Survey 
reports, was supposed to be of great extent and value; but the 
large masses, which characterized the mines soon gave out; and 
while mining has been continued more or less ever since, the yield 
has been comparat vely trifling. 

Virginia. — The only place in this State, from which corundum 
has been reported is Bull Mount, Patrick county. Here, in the fall 
of 1888, Mr. W. B. Rucker, of Stewart, Patrick county, discovered a 
few specimens of corundum and associate minerals. 1 The region is 
composed of mica- schist, talcose mica-schists and chloritic slates. 
Chrysolitic or serpentine rocks have not been observed in the neigh- 
borhood. It was thought, therefore, by Dr. F. A. Genth, who de- 
scribed the locality in the American Journal of Science, just cited, 
1 Am. Jour. Sc, 3d Series, Vol. XXXIX, p. 47, 1890. 



1 8 HISTORY OF CORUNDUM. 

that the corundum, which has only been found on the surface, be- 
longs to several granite dykes, which intersect these schists. The 
minerals associated with the corundum are kyanite, andalusite, raus- 
covite, margarite and chloritoid. 

North Carolina. — This State takes the lead in the corundum 
industry, not only in the number of working mines, but also in the 
amount of corundum produced. Dr. Genth tells us: — "The 
first large mass was found in 1847 on the French Broad river, three 
miles below Marshall, in Madison (then Buncombe) county. It 
was of dark-blue color, and was associated with chlorite and mar- 
garite." In 1870, Rev. C. D. Smith sketched the corundum belt of 
North Carolina, as "running in a southwesterly course across Ma- 
con county, where it strikes the Georgia state-line, its general di- 
rection coinciding with the trend of the Blue Ridge, until it reaches 
the head of the Tennessee river, when it suddenly ceases on en- 
countering the Nantegalee mountain (a spur of the Blue Ridge here 
running due north), to reappear 10 miles to the northwest on Buck 
Creek, whence it pursues its original course of northeast and 
southwest across the Chunkygal mountains, where it again enters 
the Blue Ridge. 1 Later investigation has revealed a more ex- 
tended belt. 

The last writing on the corundum deposit of the State is by E. W. 
Parker, in the United States Mineral Resources, 1893, who re- 
ports: — "The corundum is found in pockets and veins, usually from 
four to twelve feet wide, chiefly in gneiss, talc, chlorite and mica- 
schists, in massive anthophyllite, olivine or serpentinized rocks." 

The principal mines are located in Macon, Jackson and Transyl- 
vania counties. 

Georgia. — The gold washers knew of the presence of corundum 
in Georgia, " early in the forties;" but they paid no attention to it. 
About 1852, Mr. Plant, banker at Macon, Ga., sent a ruby, a small, 
red hexagonal prism, to Professor Shepard of Amherst College, 
which was said to have come from a gold mine in Habersham 
county, Ga. Similar brief mention, by writers of the period of 1870, 
place the knowledge of its presence in Georgia, at an early date in 

1 C. U. Shepard, Am. Jour. Sc, 3d Series, Vol. IV, 1872. 



HISTORY OF CORUNDUM. 1 9 

the American history of corundum; yet there seems to have been 
no systematic search made for the mineral, at this time. About 
1870, Mr. William R. McConnell, of Hiawassee, Towns county, an 
enthusiastic explorer, found a considerable quantity of surface corun- 
dum on his estate; and, not knowing what it was, he piled it up for 
later determination. Shortly after, a specimen of this was shown 
to Rev. C. D. Smith, who immediately recognized it as corundum. 
About the same time, also, corundum was found by Mr. Thompson 
at Laurel Creek, Rabun county. 

Interest, however, in Georgia occurrences was not fully awakened, 
until Dr. H. S. Lucas of Massachusetts opened up the Laurel 
Creek property. Since then, corundum has been searched for, in 
the northern counties, even by children. 

South Carolina. — The corundum, found thus far in South 
Carolina, has attracted little attention. Its occurrence here is un- 
doubtedly similar to that of North Carolina and Georgia. In the 
Resources of South Carolina, published in 1883, by the State Board 
of Agriculture \ corundum is merely mentioned as a mineral occur- 
ring in Laurens, Anderson and Oconee counties in arnica-slate (?). 

Alabama. — Dr. Eugene A. Smith, State Geologist, in answer to 
my letter of inquiry concerning the history of corundum in Alabama 
wrote : — " Corundum was first discovered in Alabama, near Dudley- 
ville in Tallapoosa county about the year '72 or '73. The first 
notice of it was published by the Rev. C. D. Smith of North Caro- 
lina, who was searching for asbestos for a company. It has since 
been found in the neighborhood of Hanover, Coosa county. The 
Tallapoosa variety has been found only in loose pieces embedded in 
the soil, and has, as far as I know, not been found in place, there. It is 
associated with steatite, hornblendic and pyroxenic rocks, and, also, 
with tourmaline, asbestos and feldspar. In the Coosa county locality, 
the corundum appears to be enveloped in a thin coating of talc. 
Corundum has never been of any economic use in Alabama, princi- 
pally for the reason, that the original vein has never been exposed, 
and nothing but more or less altered fragments have been obtained." 

1 South Carolina Resources etc., p. 137, 1883. 



20 HISTORY OF CORUNDUM. 

Montana. — According to Mr. G. B. Foote, one of the pioneers 
of Helena, corundum in the form of the precious stones, ruby and 
sapphire, was first discovered at Eldorado Bar, in December, 1865; 
but the earliest mention of finding sapphires in this State dates 
back to May 5, 1865, when Mr. E. R. Collins, an earnest and re- 
liable prospector, found them on claim No. 4. Dr J. L. Smith 
called attention to this discovery in the American Journal of Science, 
in September, 1873. 

The gems were discovered in the sluice boxes of the placer 
mines. In a short time, after having determined the limits of the 
precious stone bearing sands, a company was formed in London, 
under the title, " The Sapphire and Ruby Company of Montana, 
Limited," and the country was worked for both alluvial gold and 
precious stones. Since this time, the Montana fields have increased 
somewhat in importance, and are now recognized by the trade, as 
one of the sources for sapphires of medium grade, no true red rubies 
or true blue sapphires having been found. The rocks in the vicin- 
ity are limestone, quartzite and dark argillaceous slates. These are 
broken through and intersected by dykes, some of which have been 
described as mica-augite-andesite. In these dykes are found well 
defined crystals and rounded masses of sapphires, and other min- 
erals. This, then, is the probable source of the innumerable sap- 
phires, found in the alluvial deposits. 

Colorado. — Corundum was first found in this State in 1882, at 
the Calumet iron mines, situated in Chaffee county; this is the only 
locality known at present. It is found in small tabular crystals, 
mostly blue, though some are white. The crystals show the 
basal planes and rhombohedral faces, only; no prisms have been 
observed, in any instance. It occurs in siliceous and micaceous-schists, 
in which appear occasional pegmatitic bands. This has been meta- 
morphosed, by intrusions of diorite. The associated minerals are 
quartz, feldspar, yellow mica, a little rutile and grains of magnetite. 
Mr. R. C. Hill, Geologist of the Colorado Fuel and Iron Company, 
Denver, to whom I am indebted for the information, says, that the 
" ore" is bunchy; but there seems to be a large quantity of it, the 
excavation showing it to extend one thousand feet on the outcrop. 



HISTORY OF CORUNDUM. 



21 



At the time he wrote, they were having a car-load put through 
the concentrating mill, with a view to finding out what could be 
done with it. 

California. — No mention is made of corundum in the reports 
of the State Mineralogist. Dana, however, reports it, in Los 
Angeles county, in the drift of San Francisqueto Pass. Personal 
letters, from several of the leading mineralogists in the State, con- 
tain the same reply: — "The only knowledge we have of the occur- 
rence of corundum in California is that, given in Dana's System of 
Mineralogy." It is evidently very rare. 

NOMENCLATURE OF CORUNDUM. 

The terms applied to the varieties of corundum are various, and 
have been much confused. This is accounted for, not only by the 
very early knowledge of this mineral, but, principally, from the 
fact, that only in the early part of this century were these varieties 
united under one head. Dr. Thomas Egleston, l of the School of 
Mines, Columbia College, has tabulated the following list of terms 
found in literature, past and present: — 

Corundum. 



Adamant, Kirwan. 

Adamantine spar, Phillips. 

Adamas siderites, Pliny. 

Alumina. 

Anthrax. 

Corindon, Hauy. 

Corindon Adamantine, Brongniart. 

Corindon Harmophane, Hauy. 

Corivendum. 

Corivendum, Woodward. 

Corundite. 



Demantspath, Klaprath. 

Diamond spar. 

Gyrasole, Kirwan. 

Imperfect corundum, Greville and Bournon. 

Karund, Hind. 

Korund, Werner. 

Rhombohedral corundum, James. 

Rhombohedrischer corund, Mohs. 

Soimonite. 

Spath adamantine, Delam. 

Thoneride. 



Catalogue of Minerals and Synonyms, by T. Egleston. 



22 



HISTORY OF CORUNDUM. 



Sapphire. 



Hyacinthos, Greek. 

Anthrax, Theophrastm. 

Amethyste orientale. 

Apyrote. 

Asteria, Pliny. 

Asteriated sapphire. 

Asterie. 

Barklyite. 

Blue du roi. 

Blue sapphire. 

Carbunculus. 

Cat sapphire. 

Corindon harmophane. 

Corindon hyalin, Hauy. 

Corindon perfect. 

Corindon telesie, Brongniart. 

Emeraude orientale. 

Hyacinth. 

Hyacinthos. 

Lichnis, Pliny. 

Luchs saphir. 

Luchs sapphire. 

Lynx sapphire. 



Opalescent sapphire. 

Oriental amethyst. 

Oriental aquamarine. 

Oriental chrysolite. 

Oriental emerald. 

Oriental hyacinthe. 

Oriental persodot. 

Oriental ruby. 

Oriental sapphire. 

Oriental topaz. 

Orientalisk rubin, Wallerius 

Rubie etoile. 

Rubin. 

Rubis. 

Rubis oriental, salamstein, Werner. 

Salamstone. 

Saphir, Werner. 

Saphir asterie. 

Saphir blanc. 

Saphir de chat. 

Saphir etoile. 

Saphir. 



Emery. 



Acone ex Armenias, Theophrastus. 

Smiris. 

Dioscorides. 

Armenian Whetstone. 

Corindon granuleux, Hauy. 

Emeri. 

Emeril, Hauy. 

Emerite, Shepard. 

Fer oxyde quartzifere, Hauy. 

Granular Corundum. 



Grinding spar. 

Naxium. 

Naxium ex Armenia. 

Pyrites vivus, Pliny. 

Schmergel. 

Schmirgel. 

Smiris, Agricola. 

Smiris ferrea, Wallerius. 

Smiris. 



CHAPTER II. 



VARIETIES OF CORUNDUM. 



Introductory Remarks. 

Sapphire. 

Corundum. 

Emery. 

Physical Properties. 

Artificial Products. 



INTRODUCTORY REMARKS. 

When the oxide of aluminum is found in the native state, it is 
known as corundum. The name corundum is derived from the 
Hindoo word Kurand (corundum stone) — corundum being prob- 
ably first known in Europe from the Indian import. Three vari- 
ties of corundum are recognized, viz. : — 

i. Sapphire, 

2. Corundum, 

3. Emery. 

This classification was adopted early in the century, and the same 
is recognized in the arts to-day. Previous to this time, owing to 
differences in color, hardness, degree of transparency, and state of 
crystallization or structure, they were considered as distinct species. 
In 1805, they were united under one head by Hauy, although rela- 
tionship of species in crystallization had been observed by the early 
crystallographer, Rome de Lisle. 

The oxide of aluminum in its purest state is perfectly colorless 
and transparent; but it is seldom found in this condition ; corundum 
is generally tainted by some oxide of metal. The purer kinds of 
fine colors, transparent and translucent and useful as gems, are 
known as sapphires; the dull colors, not transparent, are called 
corundum; while the black or grayish-black variety intimately 



VARIETIES OF CORUNDUM. 



mixed with oxide of iron, either magnetite or hematite, is distin- 
guished as emery. 

SAPPHIRE. 

The variety termed " Sapphire " includes all those kinds of 
corundum, which, on account of their purity in color, transparency 
and translucency, may be used as gems. Under this head, there- 
fore, are grouped many stones having individual names. For sim- 
plicity in classification, jewelers have adopted the following table. 
It will be observed in this table that shades of red are classified as 
" Rubies," while any other color, or those destitute of color, pass 
under the head of " Sapphire" : — 

jeweler's classification of sapphire. 



Sapphire. 

True Sapphire blue. 

Sapphire shades of blue. 

Sapphire, 

(Diamond Spar) ) ,.. 

( Adamas, Pliny) . . . \ whlte ' 

Oriental Topaz yellow. 

Oriental Emerald sreen. 



Euby. 
True Euby or Oriental Ruby. . ] 

Anthrax (Theophrastus) ! •, 

Carbunculus f recu 

Lychnis (Pliny) J 

Ruby shades of red. 

Oriental Amethyst purple . 



Star Sapphire Asteria (Pliny). 

Ruby. — This is pre-eminently the most important of the " pre- 
cious stones " of this species. Its marvelous beauty, which induced 
worship from the ancients, has ever awakened an allied feeling in 
the hearts of Christians. Stones of true " pigeon's blood " color 
are extremely rare and valuable. Burma, Siam and Ceylon are 
practically the only commercial fields ; and, of these, Burma alone 
has become celebrated for the production of the true color, though 
occasionally fine gems are found both in Siam and Ceylon. Ac- 
cording to Mr. Edwin W. Streeter, 1 their original matrix was 
probably crystalline limestone, the disintegration of which has left 
them distributed along the hills and valleys and on the floor of 
limestone caverns. The typical ruby-bearing earth seems to be a 
yellowish clay, known locally as Byon. 

1 Any one interested in the study of gems will be well repaid to read his admira- 
ble work entitled " Precious Stones and Gems," 5th edition, published by George Bell 
■& Sons, Covent Garden, London. 



VARIETIES OF CORUNDUM. 2$ 

The value of rubies of true color depends largely upon judicious 
cutting, size and flawlessness. A perfect ruby of one carat weight, 
or more, has always taken precedence of the diamond in value. Of 
the two, equally perfect and five carats in weight, the ruby will 
bring ten times the price of the diamond. Above ten carats, the 
value of such a ruby is inestimable. This may be better illustrated 
by a well known sale, in which the rubies were considered to have 
been sold at a great loss. In 1875, the necessities of the Burmese 
Government compelled it to sell to the London market two rubies, 
which connoisseurs pronounced the finest ever seen. They weighed, 
when recut, one 32 5-16, the other 38 9-16 carats. They were sold 
for $50,000 and $100,000, respectively. 

Sapphire. — The sapphire was ranked by the ancients, almost as 
high, if it was not held in quite as close esteem, as the ruby. To it r 
as to the ruby, they ascribed wonderful properties, and prized it exalt- 
edly. As with the ruby, commerce knows only of a few localities,. 
*n which it is found in sufficient abundance to pay for mining. 
These are Siam, Burma, Cashmere and Ceylon, Siam yielding the 
most beautiful and perfect stones. Owing to large finds, which 
have been made in the East, within the last fifteen years, the sap- 
phire has greatly depreciated in value, though exceptionally fine 
stones are still highly prized. 

The finest sapphire in the world came from India. It is a richly 
colored blue stone, and weighed, on arrival in Europe, 225 carats.. 
Owing to a flaw, it was recut into a gem of 165 carats. This was 
sold in Paris, and was estimated to be worth from $35,000 to 
$40,000. 

Star Sapphires. — There are certain varieties of corundum, which 
show a stellate " opalescence," or a star of light, when viewed in 
the direction of the vertical axis of the crystal. This is especially 
true of the grayish-blue translucent sapphires. Furthermore, there 
are purple and reddish shades of ruby, which, when properly cut, 
also show this asterism. Stones of such character are known as 
" Star Sapphires." 

The optical phenomenon here presented is due to the internal 
structure of the stone. All star sapphires show the laminated 



26 



VARIETIES OF CORUNDUM. 



structure, and, on the basal planes, lines radiating from a common 
center. The action of the light on these radiating lines gives rise 
to a star-like opalescence, which is very attractive. Star sapphires 
have increased in value in the past few years ; but this value is 
very small, unless they are of finest rank and color. Small star 
sapphires range from ten dollars upward. The finest star ruby, 
lately seen in England, was valued at $10,000. 

How to Select Sapphires. — In the selection of sapphires, one 
must guard particularly against imperfections ; for the sapphire is 
typically imperfect. An examination, in person, of a first-class jew- 
eler's collection of sapphires, revealed, out of a hundred stones, only 
two or three free from defects. The common defects are an im- 
perfect transparency, clouds, spots partially opaque, massing of 
color at one spot, fine dark lines, white glassy stripes, rents, knots 
and silky flakes on the table of the stone. These defects are fre- 
quently observable to the naked eye ; but their presence is ren- 
dered more evident by the use of a lens. An expert gem-cutter 
will so cut a sapphire, with its color massed at one spot, as to cause 
the color to be dispersed by the reflection of the light against the 
facets. The color of the sapphire is often merely a matter of taste ; 
yet, to the trade, color is most important, and " true colors " are 
recognized. The most valuable ruby has the color of " pigeon's 
blood," while the true sapphire must have the characteristic velvety 
appearance of the blossom of the little " corn flower." 

CORUNDUM. 

The variety, corundum, includes all semi-transparent and translu- 
cent kinds of corundum, not useful as gems; also, all the dull and 
opaque kinds, except emery. Three types are commonly distin- 
guished in mines, viz: — 

1. Sand-Corundum. 

2. Block-Corundum. 

3. Crystal-Corundum. 

Sand- Corundum. — This is a granular corundum, coarse or fine, 
usually found embedded in a gangue of vermiculites or of decom- 



VARIETIES OF CORUNDUM. 2 7 

posed feldspar. In some veins, it occurs free, while in others, 
alteration or associate minerals, commonly albite, margarite or da- 
mourite (a variety of muscovite), wrap it closely, forming a crust, 
which frequent washing will not remove; a machine for the purpose 
is required. Sometimes, it is penetrated by vermiculite scales. The 
color of sand-corundum is usually gray to grayish-blue, although 
red is common, and all the other colors may be detected. This is 
much the most productive of corundum found, and, therefore, the 
most worked. Moreover, veins of this character seem universally 
present in corundum mines. 

Block-Corundum. — This includes the massive corundum with 
nearly rectangular parting or pseudo-cleavage. The largest spec- 
imen of this kind, known to have been found, was taken from the 
Laurel Creek mine, Rabun county, Ga., and was said to weigh 
over 5,000 pounds; other immense blocks have been taken from 
the same mine, on account of which the mine is frequently 
called a "block-corundum mine." Veins, however, of this char- 
acter, that is, in which the corundum is massed in such large bodies, 
although extremely rich at times, are usually abandoned as non- 
paying. 

Crystal-Corundum. — Crystal corundum is quite common, and 
includes all corundum possessing crystal form. It is present, with 
both the sand and the block-corundum, and ranges in size from very 
minute crystals to those of magnificent proportion. Among the 
largest crystals ever found were some, which were taken from the so- 
called block-corundum veins at Laurel Creek mine, during the sum- 
mer of 1893; they are now in the possession of Dr. H. S. Lucas. 
A description of these is given with figure 2. Corundum crystals are 
usually rough, and seldom transparent; this is especially true of 
large crystals. Frequently, moreover, the large crystals do not 
possess a uniform color; but patches of gray, blue and red tints 
blend into each other. The most common type in Georgia and 
North Carolina are six-sided prisms, usually with the basal plane, 
and quite frequently terminated by a pyramid. Fuller particulars 
on these types will be omitted, to avoid repetition, later. 



28 



VARIETIES OF CORUNDUM. 
Pig. 2. 





Large Corundum Crystals from the Laurel Creek Corundum Mines, Rabun County, 
Georgia. 1. Height, 14 inches, diameter, 8J inches. 2. Height, 16 inches. 



EMERY. 

Emery is an intimate mixture of corundum and magnetite or 
hematite. It is without crystal form, and has the appearance of a 
fine grained iron ore, which it was thought to be, for some time. 
Its hardness is due to the presence of corundum; and this, together 
with its abundance, makes it very desirable as an abrasive agent. 
Emery has been supplied to the world many years from the Gre- 
cian islands, where it has been known and used, for thousands of 
years. Here it is found in a bluish metamorphic marble, inter- 
bedded with mica-slate and gneiss. Its occurrence is in the form 
of nodules and large irregular masses, some of which are several 
yards in diameter and up to forty tons in weight. These large 
pieces, unless fissured, are broken with great difficulty, on account 
of the compactness of the grain. Since the transportation from 
the quarries is only on the backs of horses and camels, those masses 
which will not yield to the hammer are exposed to the action of fire 
for several hours, and are thus broken up. Dr. J. Lawrence 
Smith's investigations for the Turkish Government, and his discov- 
eries of 1847, so increased the known area of emery in that region, 



VARIETIES OF CORUNDUM. 29 

that the monopoly, exercised by the owners of the Greek property, 
was completely broken, and the price was reduced more than one- 
third. Following Dr. Smith's discoveries, and consequent, in a 
great measure, upon his able reports on the geological relations, 
emery was discovered in other parts of the world. In the United 
States, in 1863, Professor Jackson discovered a vein of emery at 
Chester, Mass. 1 The greater portion of emery, however, used in 
this country comes from the Grecian islands, and is known to the 
trade as Naxos emery or Turkish emery. "For the decade ending 
with 1878, our average annual import of emery ore was 2,376,743 
pounds. For the decade ending withi888,it was 7,315,165 pounds, the 
year 1888 showing the largesttotal of any year but one,duringtwenty 
years. That total was 9,643,800 pounds. While the annual import 
of ore was more than tripled in the second decade, the annual aver- 
age import of granulated and pulverized emery slightly decreased. 
That annual average import was for the first decade 621,807 pounds, 
and for the last, 589,054 pounds. The total annual average import of 
ore and grain for the first decade was 1,338 tons, and for the second, 
3,521 tons." 2 It will be seen, by table on page 113, that the increase 
has been, on the average, continuous up to date. 

Very little emery has thus far been found in North Carolina, and 
none in Georgia. In 1893, 3 emery was discovered on Skeena 
creek, five miles from Franklin, Macon county, North Carolina. 
The abundance of the deposit has not been reported. 

PHYSICAL AND CHEMICAL PROPERTIES. 

Chemical Composition. — The formula for corundum is written 
Al 2 O s . Sapphire and common corundum are considered essentially 
pure oxides of aluminum, while emery is an intimate mixture of 
corundum with an oxide of iron, either magnetite or hematite. 



1 See this report, under Massachusetts, p. 15. 

2 T. Duncan Paret; Journal of the Franklin Institute, March, 1890. 

'Mineral Kesources of the U. S., 1893, p. 675. 



3o 



PHYSICAL AND CHEMICAL PROPERTIES. 



Analyses of corundum and emery, made by Dr. J. Lawrence 
Smith, are as follows: — 



LOCALITY. 



<DrG 

<u a o. 

5*00 



o 



ft 

CO 



COMPOSITION. 



2 

'■3 ,2' 



Emery. 

Kulali 

Samos 

Nicaria 

Kulali 

Naxos 

Nicaria 

Naxos 

Ephesus. 

Kulali 

Corundum. 

Sapphire of India 

Ruby of India 

Corundum, Nicaria . . . 
" Asia Minor 

Asia 

India...... 

Asia 

India 

Emery. 
Chester, Mass 



57 
56 
56 
53 
46 
46 
44 
42 
40 



4.31 
3.89 



1.90 
2.10 
2.53 
2.36 
4.73 
3.10 
5.47 
5.62 
2.00 



63.50 
70.10 
71.06 
63.00 
58.53 
75.12 
69.46 
60.10 
61.05 



32.25 
22.21 
20.32 
30.12 
24.10 
12.06 
19.07 
33.20 
27.15 



0.92 
0.62 
1.40 
0.50 
0.86 
0-72 
2.81 
0.48 
1.30 



1.61 
4.00 
4.12 
2.36 
3.10 
6.88 
2.41 
1.80 
9.63 



100 
90 
77 
65 
60 
58 
57 
55 



4.06 





97.51 


1.89 




97.32 


1.09 


1.60 


92.39 


1.67 


0.68 


87.52 


7.50 


1.66 


86.62 


8 21 


2.86 


93,12 


0.91 


3.74 


87.32 


3.12 


3.10 


84.56 


7.06 J 



1.12 

0.82 
0.70 
1.02 
1.00 
1.20 



0.80 
1.21 
2.05 
2.01 
3.85 
0.96 
2.61 
4.00 



33 






44.01 


50.21 




40 






50.02 


44.11 




39 






51.92 


42.25 




45 






74.22 
84.02 


19.31 
9.63 





3.13 
3.25 
5.46 

5.48 
4.81 



PHYSICAL AND CHEMICAL PROPERTIES. 



31 



Fig. 3. 




Crystal Forms of Corundum. 



32 PHYSICAL AND CHEMICAL PROPERTIES. 

Crystal Form and Structure. 1 — Corundum crystallizes in 
the Rhombohedral Division of the Hexagonal System. The crystals 
are usually doubly terminated, six-sided pyramids or six-sided prisms, 
terminated by the basal plane, and, not unfrequently, they are in 
tabular crystals or six-sided plates. The pyramidal and prismatic 
faces are more or less deeply striated or grooved horizontally. The 
basal planes or truncated ends of the crystals are striated parallel 
to the edges, or divided into sectors by lines radiating from the 
center. The latter, when cut en cabochon, that is with a convex face 
simply polished, reflects, from the convex surface, a star of light (as- 
terism). If the crystals are large they are usually rough and 
rounded. Most specimens found are rolled pieces and fragments. 
It also occurs massive in coarse and fine grains. Twins occur, 
either as penetration or polysynthetic forms, most frequently the 
latter. In both cases, the twinning-plane is the rhombohedron. 
When the twins are polysynthetic, that is, when the twinning-planes 
of the aggregate of individuals continue parallel to each other, a 
laminated structure is produced. This structure gives rise to the 
pseudo-cleavage or parting, so common in corundum. 

Cohesion. — Cleavage is due to minimum cohesion. In corundum 
there is no true cleavage, but a pseudo-cleavage, due to parting. 
Parting should be clearly distinguished from cleavage. Cleavage is 
the natural fracture along the plane of minimum cohesion or least 
resistance ; parting is a plane, in which the cohesion is minimum, 
because the structure is lamellar through twinning, or in which the 
cohesion has been reduced to a minimum by pressure. Parting in 
corundum is sometimes perfect, but interrupted, parallel to the basal 
plane. There is also a parting parallel to the rhombohedron. The 
former parting is due to pressure, and the latter to twinning. 

Corundum is extremely brittle, except when compact; then it is 
tough. A broken surface shows an uneven to conchoidal fracture. 

1 The best text-book in English on crystallography is published by Henry Holt & 
Co., New York City, entitled, " Elements of Crystallography," by Dr. George H. 
"Williams, late Professor of Geology at Johns Hopkins University. Those, interested 
in the collection and study of minerals, and who desire more information on crystal 
structure, than is commonly found in mineralogies, will do well to provide themselves 
with this little book. 



PHYSICAL AND CHEMICAL PROPERTIES. 33 

The hardness of corundum is 9. 1 It will be seen, by the table of 
analyses made by Dr. Smith, 2 that there is a considerable difference 
in hardness between different varieties of corundum, and between 
specimens of the same variety from the same or different localities. 
This will be considered in the chapter on economics. 

Specific Gravity. — The density of corundum, as compared 
with that of water as a standard, assumed to be 1, varies but slightly 
from 4. This quantity is not constant, owing to the variations in 
chemical composition and physical structure. 

Optical Properties. — The luster of emery is metallic, or the 
luster of metal; of the other varieties of corundum, it is adamantine 3 
to vitreous. 4 The color of corundum varies, not only in different lo- 
calities, but in the same locality — ranging from white to brown, viz., 
white, gray, blue, red, yellow and brown. Emery is dark-blue to 
black; its streak is uncolored. Pleochroism, or that property, which 
certain minerals possess of showing a different color, when light is 
transmitted through a crystal in different directions, is observed in 
the deeply colored specimens of sapphire. Spinel and garnet, min- 
erals often confused with sapphire, do not possess this property on 
account of their crystalline character; and hence, by means of the 
dichroscope, an instrument so constructed, that the result of light 
transmitted in two directions may be compared side by side, this 

1 Many minerals, which, to the average observer, resemble each other closely, may be 
readily distinguished by their hardness. This is especially true of corundum, and 
minerals bearing a striking resemblance to it. Mohs has made out a table of ten 
minerals, with which all minerals are now compared. The determination is made by 
the resistance a smooth surface offers to scratching. It may be well to state, in re- 
gard to the following table, that there is a greater difference between corundum and 
diamond, than between talc and corundum, a break, which we have no known natural 
minerals to bridge. 

MOHS' SCALE OF HAKDNESS. 

1. Talc. 6. Feldspar. 

2. Gypsum. 7. Quartz. 

3. Calcite. 8. Topaz. 

4. Fluorite. 9. Corundum. 

5. Apatite. 10. Diamond. 

2 See page 30. 

3 The luster of the diamond. 

4 The luster of broken glass. 



34 ARTIFICIAL PRODUCTION OF CORUNDUM. 

distinction can be readily made. The diaphaneity * of sapphire 
varies from transparent to translucent; of corundum, from trans- 
lucent to opaque; while emery is opaque. The index of refraction 2 
of. corundum is 1.76. This high index of refraction accounts for 
the great brilliancy, when the gems are properly Cut and polished. 

ARTIFICIAL PRODUCTION OF CORUNDUM. 3 

Synthetical mineralogists discovered some years ago, that the 
pure forms of corundum could be reproduced artificially. Increase 
in knowledge in synthetical chemistry, in the past ten years, has 
enabled workers in this field to effect the most admirable results in 
the case of corundum, not only in the production of sapphires, but 
also in the size of the crystals produced. Gaudin, by means of 
charcoal, decomposed potash-alum and formed corundum. Ebel- 
men, by exposing four pints of borax and one of alumina to a high 
heat, produced crystals of corundum. The result of Deville and 
Caron's works (the subjection of aluminum to the action of boric 
acid in a carbon vessel) was corundum, in large rhombohedral 
plates; the addition of chromium fluoride, in varying amounts, gave 
color, affording blue, red and fine green sapphires. Meunier ob- 
tained corundum by the decomposition of aluminum chloride by 
magnesium and water vapor, at a high temperature in a sealed 
tube. Fremy and Feil fused alumina and minium in siliceous 
earthen crucibles, obtaining " a fusible lead aluminate, which was 
subsequently decomposed by the silica, setting free the alumina in 
hexagonal crystals of considerable size, under varying conditions, 
rubies, sapphires etc., being obtained." "Friedel 4 describes the produc- 
tion of crystals of corundum and diasporeby the wet way,by the action 
of a solution of soda and amorphous alum, at an elevated tempera- 
ture. At 450 to 500 , both corundum and diaspor were obtained; 
at 530 to 535°, only corundum; and at 400 , only diaspore." 
Fremy, in Synthese du Rubis, describes the successful reproduction 
of rubies by the reaction, at a high temperature, in an earthen 

1 Degree of transparency. 

2 Power of refracting light. 

3 Dana's System of Mineralogy, sixth edition, p. 213. 
4 Dana's System of Mineralogy, sixth edition, p. 1031. 



ARTIFICIAL PRODUCTION OF CORUNDUM. 35 

vessel, of a mixture of alumina, with more or less potash, upon 
barium fluoride, bichromate of potassium being used as coloring 
matter. The result was rubies well crystallized, clear and of bril- 
liant luster. 



CHAPTER III. 



ALTERATIONS AND ASSOCIATE MINERALS OF 
CORUNDUM. 

General Observations. 
•Oxides op Silicon. 
Hydrous Oxides of Aluminum. 
Anhydrous Oxides op Other Metals. 
Anhydrous Silicates. 
Hydrous Silicates. 
I. Micas. 
II. Clintonites. 

III. Chlorites. 

IV. Vermiculites. 

V. Serpentine and Talc. 
Phosphates. 



GENERAL OBSERVATIONS. 

Corundum undergoes many alterations, which give rise to a se- 
ries of interesting aluminous minerals. Our knowledge of these 
minerals, in their relation to corundum, is extremely limited, because 
of the few workers along this line of investigation, and the difficul- 
ties, under which they have labored. This is especially true of the 
United States, where so few places have been opened up to the 
investigator, that his scope for careful and comparative study has 
been rigidly limited, and good material, rare. To Dr. J. Lawrence 
Smith, and to Dr. F. A. Genth, especially, who made quite an 
elaborate study of corundum alteration products, we are most in- 
debted for our knowledge of these minerals. 1 As far as known, 
some of these minerals have not been observed in Georgia, w r hile 
others, although undoubtedly present, have not yet been differen- 
tiated from the group. Nevertheless, descriptions of the most 
important ones will be an aid to those interested only in mineral 

1 In the discussion of these minerals, the work of both men is used freely. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 37 

collection, while to those citizens prospecting for corundum, a 
knowledge of these minerals will be invaluable, as a guide and clue 
to the presence of that mineral, on account of their intimate rela- 
tions to it. 

OXIDES OF SILICON. 

Quartz, Chalcedony, Opal. 

Quartz. — Quartz crystals occur penetrated by corundum. Sil- 
lem T has observed quartz pseudomorphous after corundum. 

Chalcedony. — This is a cryptocrystalline 2 form of quartz. Usu- 
ally it is white, grayish- white or brown; other colors have special 
names. In mammillary and botryoidal forms, it is quite common, 
as an associate of corundum. 

Hyalite. — This is a variety of opal, an amorphous 3 form of sil- 
ica, with a varying amount of water. It has the chemical composi- 
tion of quartz plus water; but its opal condition renders it less 
hard, with a lower degree of specific gravity, and without power 
of crystallization. It has been found at Corundum Hill, Macon 
county, N. C, as a botryoidal, colorless and white incrustation upon 
foliated chlorite and upon corundum; also, of a brown color, upon 
corundum at Dudleyville, Ala. 

HYDROUS OXIDES OF ALUMINUM. 

Diaspore, Bauxite, Gibbsite. 

Diaspore. — Diaspore is a hydrated aluminum oxide, with the 
formula, A1 2 3 .H 2 = alumina 85 .0, water 15.0. Crystallizing 
with orthorhombic symmetry, it occurs in prismatic crystals, foliated 
masses, in thin scales, and sometimes in stalactitic forms. The 
crystals are usually flattened, sometimes acicular, with commonly 
rounded faces and vertical striations. It is usually not quite as hard 
as quartz, nor as heavy as corundum. The cleavage is very per- 
fect, parallel to the flattened, prismatic face. The luster is bril- 
liant, while the color is a very light shade of green, gray, brown or 

1 Sillem. Leonhaide and Brouns, Jahrbuch, p. 385, 1851. 

2 Flint-like. 

3 Incapable of crystallization. 



33 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

yellow, to colorless. Beautiful specimens have been found at Ches- 
ter, Mass., and at Unionville, Chester county, Pennsylvania. It 
has also been observed at Corundum Hill, N. C. ; and, at 
the Laurel Creek corundum mine, in Rabun county, Ga., it 
occurs in small tabular, transparent, white crystals, as an associate 
of the corundum. Dr. Genth considers it a result of the hydration 
of corundum, and asks, if, like corundum in spinel, it may not be so 
minutely distributed, as to be concealed to the sharpest investiga- 
tion. Dr. J. Lawrence Smith, in his Scientific Researches, p. 27, 
says : — " There is reason to believe, that the mineral will be found 
in almost every corundum locality." Like Dr. Genth, he thinks, 
from the fact that, when imbedded together, the line of gradation 
is imperceptible, that diaspore may be so intimately mixed with 
some corundum, as to escape detection; and hence, by means of it, 
he would explain the presence of water in many corundums. 

Bauxite. — This mineral is of especial interest in Georgia, be- 
cause the Coosa valley of Georgia and Alabama is one of the two 
localities in the United States, which yield bauxite in commercial 
quantities; the other is the Arkansas locality. The former region 
was briefly described by Dr. C. Willard Hayes, 1 Assistant United 
y States Geologist, in a paper read before the Virginia Beach meet- 
ing of the American Institute of Mining Engineers, February, 
1894. Reports upon the same region, also, have been made by 
Henry McCalley, 2 Assistant Geologist of Alabama, and Dr. J. W. 
Spencer. 3 

J. W. Hawkins's work near Hermitage, Flo}^d county, Ga., in 
1887, was the first mining of the kind done in America; and, up 
to October, 1891, 4,000 tons 4 had been taken out of 'one pit without 
reaching the bottom of the deposit. This deposit is one of many 
lying in a narrow belt, which extends from Adairsville, Ga., about 
sixty miles, to the vicinity of Jacksonville, Ala. Besides the de- 

1 The Geological Relations of the Southern Appalachian Bauxite Deposits ; C. Wil- 
lard Hayes, Trans. Am. Inst, of Mining Eng. 

2 Alabama Bauxite ; by Henry McCalley, Proc. Ala. Indus, and Sci. Soc, 1893. 

3 Geology of the Paleozoic Group of Georgia ; J. W. Spencer, 1893. 

4 Geology of the Paleozoic Group of Georgia; by J. W. Spencer, 1893, p. 228. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 39 

posit just mentioned, this mineral has been worked on a commercial 
scale at two points near Rome, Ga.; one, five miles north, the other, 
six miles south of Rome; it has also been worked near Rock Run, 
Ala. Dr. Spencer says: 1 — "The quantities of the Georgia bauxite 
are extensive; and, with the increasing demand, a large supply can 
be obtained." 

Bauxite occurs, either in round grains, disseminated or compact, 
or as earth and clay-like matter. The color depends upon the 
extent of iron staining, and is white, grayish, ochre-yellow, brown 
and red. Bauxite is another form of hydrated alumina; and it so 
closely resembles diaspore in composition, as to be given the same 
chemical composition by some authors. Dana, in his formula, how- 
ever, doubles the amount of water. Ferric oxide is usually pres- 
ent; sometimes, in large amount, replacing the alumina ; at others, 
as an impurity. 

To be marketable, bauxite must contain not more than 3.5 per 
cent, of iron or 20 per cent., or thereabouts, of silica; nor must it 
contain less than 55 per cent, of alumina. Titanic acid is generally 
present in the Coosa valley bauxite; but this is not objectionable. 
Spencer, in his chapter on aluminum, in volume just cited, has given 
the following analyses of bauxite from the belt in Georgia : — 

ANALYSES OF GEORGIA BAUXITE. 



Alumina . 
Ferric 
Oxide. 

Silica 

Water 

Titanic 
Acid. 



46.72 

2.14 
29.01 
20.15 

0.87 



52.13 

1.12 
19.56 
24.21 



39.75 

1.62 

41.47 
16.14 



56.10 

10.64 
2.56 
30.10 



58.61 



2.63 
8.29 
27.42 



43.18 

8.74 
28.11 
19.22 



36.86 

1.28 
40.02 
20. G4 



59.82 

2.16 

6.62 

31.10 



51.22 

4.83 
13.31 

29.82 



53.31 

12.92 
1.16 
29.60 

3.22 



45.21 

0.52 

35.88 
17.13 



61.25 



1.82 
1.98 
31.43 



13 



67.53 

trace. 
2.92 
1.31 

28.00 



60.61 

0.21 
4.18 
2.47 

32.00 



60.63 

trace. 
4.76 
3.20 

31.00 



68.82 

0.21 
2.13 
4.04 

31.50 



No single hypothesis has yet been offered to explain acceptably 
all occurrences of bauxite. The bauxite of Southern France ap- 
parently originated by the breaking down of basalt and its subse- 
quent residual deposition. The origin of the Arkansas deposits, 
which occur in well stratified beds in tertiary rocks, is connected, by 



1 Geology of the Paleozoic Group of Georgia; by J. W. Spencer, 1893, p. 223. 



4<> ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

State Geologist Branner, with the contact eruptives; while the 
Georgia deposits, Dr. Spencer evidently considers, to have been 
formed by the precipitation of alumina " in the lagoons, in which the 
ferruginous and manganiferous clay-limestones were being formed. " 
The alumina, he considers, to have been derived from the weath- 
ering of the country rocks. Dr. Hayes, on the other hand, who 
has made an admirable map of the region, and given it much 
study, finds l the deposits of the Coosa valley to be directly 
upon faulted contacts, and concludes that "such enormous disloca- 
tion of the strata generated a large amount of heat. The fractures 
facilitated the circulation of water; and, for considerable periods, the 
region was probably the seat of many thermal springs. These 
heated waters appear to have been the agent, by which the bauxite 
was brought to the surface in some soluble form, and there pre- 
cipitated." This accords with the theory of Auge, who has called 
attention to the formation of hydrated alumina in the Yellowstone 
region. 

The association of bauxite with corundum has been noted in the 
bauxites of Southern France. Here occasional grains of corundum 
have been observed enclosed by bauxite. This called forth the in- 
teresting remark from T. Sterry Hunt, 2 that sufficient heat will con- 
vert bauxite into corundum, and that these grains of corundum 
encased in bauxite would seem to show, that even, at ordinary tem- 
peratures, the change may take place. Dr. Genth 3 denies this 
flatly, saying that, on the contrary, this proves quite conclusively to 
him, that the presence of corundum in the bauxite shows the 
bauxite to be the alteration product of corundum. 

Attempts have even been made, to explain, by common origin, 
the bauxite and corundum formations of Georgia on the ground, 
that the corundum belt is a direct continuation of the bauxite belt. 
In conclusion, I might say, that, whatever may be the relation be- 
tween corundum and bauxite in Southern France, any attempt to 

1 The Geological Relations of the Southern Appalachian Bauxite Deposit; by C. 
Willard Hayes— Trans. Amer. Inst. Min. Eng., 1894. 

2 T. Sterry Hunt, Amer. Jour, of Sc, 2nd series, Vol. XXXII, p. 288. 

3 Contri. from Lab. Univ. Pa., No. 1, F. A. Genth, p. 13. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 4* 

harmonize the two belts in Georgia must show an utter failure, to 
appreciate their wide differences in geological relations. 

Gibbsite. — This is a rare mineral, and has been observed only 
in two localities, in connection with corundum. Dr. Smith 1 men- 
tions two specimens of hydrargillite (an old name for gibbsite) from 
Gumuch-dagh, one a hexagonal prism, the other coating a crystal 
of corundum. The former, Dr. Genth, presumes to have been a 
pseudomorph after corundum. T. S. Seal 2 found at Unionville, Pa., 
gibbsite in the form of mammillary crustations, coating albite. 

The composition of gibbsite is given as A1 2 3 .3H 2 = alumina, 
65.4, water, 34.6. It crystallizes in the monoclinic system, in a 
tabular form. It also occurs in stalactitic, mammillary and incrust- 
ing forms. It is tough, with an eminent cleavage parallel to the 
basal plane. The color is white, grayish, greenish or reddish- 
white. When breathed upon, it has a clayish odor. 

Dr. Spencer 3 mentions the occurrence of stalactitic, mammillary 
and incrusting forms, found on the Barnsley estate, Floyd county, 
Ga., in connection with bauxite. It has not yet been seen in any 
corundum locality in this State. 

ANHYDROUS OXIDES OF OTHER METALS. 

Spinel, Hematite, Butile, Ilmenite, Titanite. 

Spinel. — Spinel is the name given to a mineral of the Isometric 
system, whose formula is MgAl 2 4 , it being one of the principal 
species of the spinel group, which bears its name. Of its four 
varieties, ruby spinel is a common associate with the true ruby; 
picotite is common in peridotites and the serpentine derived from 
them; and hereynite has been described by Professor G. H. Wil- 
liams, as an associate of magnetite and corundum, in the " Cort- 
landt Series." 

The spinel of Corundum Hill, Macon county, N. C, is gen- 
erally massive, coarsely to finely granular, and black or dark- 

1 Scientific Kesearches; J. Lawrence Smith, page 26. 
2 T. S. Seal, Amer. Jour, of Sc, 2nd series, Vol. XI, page 267. 
3 Geology of the Paleozoic Group of Georgia; J. W. Spencer, 1893, page 213. 
4 



4 2 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

green in color. It has been found to be mixtures of several spinels. 
From this locality, Colonel Joseph Willcox, of Philadelphia, has a 
pseudomorph of black spinel after corundum, the crystal being en- 
closed in a foliated chlorite. At Dudleyville, Tallapoosa county, 
Ala., black spinel, surrounded by patches of yellowish-white, cleav- 
able corundum, occurs in chlorite. 

Gahnite, a zinc spinel, with the formula, ZnAl 2 Q 4 , was ob- 
served by Dr. Smith in association with the corundum ac Gumuch- 
dagh, Asia Minor. 

Magnetite, the proto-sesquioxide of iron, FeO.Fe 2 , forms a 
part of most emery, and is present in the country rocks. 

Chromite, FeCr 2 4 , the principal ore of chromium, is seldom ab- 
sent from the chrysolites of corundum formations, where it occurs 
as a constituent of the rocks, in veins, in bedded masses, and dis- 
seminated in minute crystals through the chrysolite. Embedded 
masses of it occur at Hog Creek, near Hiawassee, Towns county, 
Ga., where it is encrusted with genthite. 

Hematite. — Hematite is sometimes associated with corundum, 
as an intimate mixture, forming in part the variety of corundum 
known as emery. 

Rutile. — This is a rare associate of corundum. 

Ilmenite. — This mineral is found associated with corundum in 
New York State; also at Chester, Mass. With it are generally 
present rutile, spinel etc. 

Titanite. — This mineral is, in rare instances, an alteration prod- 
uct of rutile and ilmenite; hence it is sometimes present with 
corundum. 

ANHYDROUS SILICATES. 

Enstatite, Anthophyllite, Amphibole (Tremolite, Actinolite, Asbes- 
tus, Smaragdite), Chrysolite, the Feldspars, Zoisite, Fibrolite, Kyanite, 
Tourmaline, Staurolite. 

Enstatite. — Good specimens of enstatite have been found at the 
various corundum mines in North Carolina, associated with corun- 
dum. Enstatite is an orthorhombic member of the pyroxene group, 
having the formula, MgO.SiO a = Silica 60, magnesium 40 = 100 ; 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 43 

sometimes a little iron is present with the magnesium. In color, it 
is grayish-white, yellowish-white, greenish-white to olive-green and 
brown, according to its percentage of iron. Distinct crystals are 
rare, and of prismatic habit. It usually occurs massive, fibrous or 
lamellar. 

Anthophyllite. — This mineral crystallizes in the orthorhombic 
system, and is an orthorhombic member of the amphibole group. 
It is a magnesium ferrous silicate (Mg,Fe)SiO s , and corresponds 
to enstatite, bronzite and hypersthene of the pyroxene group. 
Crystals are rare, and of prismatic habit. In association with 
corundum, it is commonly lamellar or fibrous massive, often occur- 
ring in forms resembling asbestus. It forms part of most corun- 
dum-bearing formations, as massive rock, in which anthophyllite 
is frequently radially arranged with actinolite. The color of an- 
thophyllite is usually of a brownish shade, sometimes of a clove- 
brown, from which its name is derived. 

Tremolite. — Tremolite is a calcium-magnesium variety of the 
species, amphibole ; its formula is Ca Mg 3 Si 4 12 = silica 57.7, mag- 
nesia 28.9, lime 13.4 = 100. Ferrous iron replacing magnesium is 
frequently sparingly present, only up to 3 per cent. It crystallizes 
in the monoclinic system in distinct crystals, which are often in 
thin, flat blades. It is white to dark-gray in color, and sometimes 
transparent and colorless. Tremolite has been distinguished at 
various corundum mines in North Carolina, and at the Laurel Creek 
corundum mine in Rabun county, Ga. 

Actinolite. — Actinolite, another variety of the amphibole 
species, has been distinguished at all the Georgia corundum prop- 
erties. It occurs also in the Pennsylvania and North Carolina 
corundum localities. It is a calcium-magnesium-iron amphibole, 
with the formula, Ca(Mg,Fe) 3 Si 4 12 . Its color, due to ferrous 
iron, is bright-green and grayish-green. It crystallizes in the mon- 
oclinic system. The crystals are common, either short or long 
bladed, as in tremolite ; it also occurs columnar, fibrous and gran- 
ular-massive. Beautiful specimens of bright-green columnar crys- 
tals, several inches in length, and often fully one third of an inch 
in width (longest horizontal axis), are found in talc, south of Ac- 



44 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

worth, Paulding county, and near Monroe, Walton county, Ga. 
Talc is the most frequent matrix of this mineral. 

Asbestus. — Tremolite, actinolite and other varieties of am- 
phibole (except those containing much alumina), when so fibrous 
that the fibers are threadlike, are called asbestus. Chrysotile, the 
fibrous variety of serpentine, is often confused with, and is much 
used as, asbestus. It is distinguished from asbestus, however, by 
the presence of water. Being fire-proof, and the finer grades 
being so easily woven into cloth, asbestus has been used for centu- 
ries. Pliny speaks of it as a " vegetable growth," and says that 
it is good for making incombustible cloth. The ancients had high 
regard for asbestus, because the cloth made from it could be easily 
made undefiled by throwing it into fire, and thus purifying it. 

Asbestus is present in many of the corundum properties in this 
State ; but, as far as observed, it is of an inferior quality. The 
fibers, though long, are without strength, and when a mass is ex- 
posed to the air, it becomes very hard on account of the presence 
of hydrous-iron sesquioxide, which has seeped into it. Various 
properties have been prospected for asbestus, and considerable of 
the material has been shipped ; but industries of this nature have 
never continued longer than a few months. In Nacoochee Valley, 
White county, a large plant has just been established, and "asbes- 
tus rock," as they call it, is being " defiberized " for the market. 

Smaragdite. — A rock, formed of a grass-green hornblende, 
feldspar and grains of pink to deep ruby corundum, has attracted 
considerable attention, because of its beauty and its occurrence in 
only a few corundum localities of North Carolina and Georgia. 
This grass-green mineral was, and is now, commonly called smarag- 
dite. Charles Upham Shepard, Sr., 1 speaks of it as arfvedsonite, 
to which it bears no resemblance. Dr. Genth, from an analysis, by 
Chatard, of a representative specimen from Cullakenee Mine, North 
Carolina, calls it kokscharqffite, after an aluminous amphibole. Ac- 
cording to the last edition of Dana's System of Mineralogy, 2 sma- 



1 Corundum Kegion of North Carolina and Georgia, by C. U. Shepard, Sr., Amer. 
Jour. Sci., 3rd series, Vol. IV., Aug. and Sept., 1872. 

2 The System of Mineralogy of James Dwight Dana, sixth edition, by Edward S. 
Dana, 1892. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 45 

ragclite is " a thin, foliated variety of amphibole, near actinolite in 
composition, but carrying some alumina. It has a light grass-green 
color, resembling much common green diallage." As a variety, 
based on color, this mineral has as much claim on mineralogists as 
hiddenite and other similar varieties. 

Chrysolite. — This mineral usually occurs in embedded grains 
with chromite, forming the so-called "chrysolite formations," in which 
the corundum of this region occurs. It crystallizes in the ortho- 
rhombic system, with crystals often flattened, and sometimes elon- 
gated. The cleavage is rather distinct in one direction, but less so in 
another, while the fracture is conchoidal. The color, as found in 
this region, is usually olive-green. The chemical formula is 2(Mg, 
Fe)O.Si0 2 , in which the magnesium and iron vary widely. Ti- 
tanium dioxide, tin and nickel are sometimes present in small quan- 
tities. It is infusible in most cases; but it is decomposed by hydro- 
chloric and sulphuric acids, with the separation of gelatinous 
silica. 

The Feldspars. — The feldspars, which are present in corundum 
localities, belong to the plagioclase species, or lime-soda feldspars, 
that is, albite and anorthite, and their isomorphous mixtures. The 
chemical composition of the theoretical albite is Na 2 3 .Al 2 0.6Si0 2 ; 
that of anorthite is CaO.Al 2 3 .2Si0 2 . All the other lime-soda 
feldspars are isomorphous mixtures of albite and anorthite = Ab n 
An m . A few, which occur most frequently, have received particular 
names. Tschermak has brought these together into a table, which 
may be enlarged by the addition of any of their compounds. The 
average specific gravity of Tschermak and Goldschmidt is attached, 
and also their hardness : — 



Species. 


Composition. 


Sp. Gr. 


Hardness. 


Albite 


Abi,An to Ab 8 ,An 


2.62 
2.64 
2.65 
2.69 
2.71 
2.75 


6-6.5 


Oligoclase 

Andesite 


Ab^A^ to Ab 2 ,An! 


6-7 


Ab 3 ,An 2 to Ab4,An 3 


5-6 


Labradorite 


Ab 1 ,An 1 to Ab 1 ,An 2 


5-6 


By townite 


Ab^A^ to Ab^Ang 




Anorthite 


Ab!,An 8 to AbojAn! 


6-6.5 



4-6 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

It will be observed, that the specific gravity increases with the 
percentage of anorthite. By means of the specific gravity, owing 
to the great exactness, with which the density of a heavy solution 
can be regulated, this determination of the feldspars is very relia- 
ble, so long as the material is pure and fresh, 'the presence of 
foreign matter, or any alteration, will lessen this certainty; for in- 
stance, a kaolinization would lessen, while the development of 
carbonates, the formation of mica etc., must increase the specific 
gravity. 

Members of this group are characterized by their brittleness, 
easy cleavage and glistening cleavage-face. Their structure is 
either compact cleavable, lamellar or granular. Their color is 
white, gray or reddish. All crystallize in the triclinic system. 

Bournon, in 1802, described, as indianite, certain white, gray 
and reddish granular feldspars, which form a matrix for corundum, 
in the Carnatic. This was subsequently discovered to be anor- 
thite. The associate feldspar with corundum at Chester, Mass., at 
Unionville, Pa., and at certain mines in North Carolina seems to be 
oligoclase. In Dr. Smith's paper, analyses of several feldspars, 
which have altered from corundum, show them to be oligoclase. 

Zoisite. — This mineral has the following chemical formula: — 
4CaO-3 Al 2 3 .6Si0 2 .H 2 == silica 39.7, alumina 33.7, lime 24.6, water 
2.0=100. The alumina is sometimes replaced by iron, thus grad- 
uating toward epidote, which has the same general formula, but 
from which it was separated some years ago on crystallographic 
ground. The crystals are orthorhombic in symmetry, with pris- 
matic type, deeply striated or furrowed vertically, and seldom dis- 
tinctly terminated. Also massive, columnar to compact. It also 
occurs commonly in crystalline masses longitudinally furrowed. 

Zoisite is brittle, with uneven fracture. The cleavage is very 
perfect parallel to the brachydome. Hardness, 6 to 6.5. On the 
cleavage face, the luster is pearly; otherwise it is vitreous. The 
color ranges from grayish-white, gray, yellowish-brown, greenish- 
gray to apple-green. A peach-blossom red and rose-red variety, 
is called thulite. 

As an associate of corundum in the United States, it was de- 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 47 

scribed under the name of unionite by Silliman, who found it at 
Unionville, Pa., in company with euphyllite. Fine specimens have 
been found at the Cullakenee Mine, N. C. Genth says of the 
latter, that many of the specimens show distinctly, that it is the re- 
sult of the alteration of corundum. The pink corundum is often 
surrounded by a thin coating of white zoisite. Other specimens 
show corundum altering on the outside to zoisite, and on the in- 
terior to margarite. 

In the corundum regions of Georgia, zoisite has been found only 
at Hog Creek mine, near Hiawassee, Towns county. 

Fibrolite. — This is a fibrous, firm and compact variety of silli- 
manite. It is sometimes radiated, and is grayish-white to pale brown 
and pale olive-green in color. It has been known for a long time, 
to accompany corundum in the Carnatic, in India, and near Canton, 
China. Interesting specimens of corundum, showing alteration 
into fibrolite, have been noticed from the Falls of the Yantic, near 
Norwich, Conn., from Burke county, N. C, from Laurens county, 
S. C, from Mineral Hill, Delaware county, Pa., and, lately, from 
several other places in North Carolina. When the alteration has just 
begun, the fibrolite appears as a very thin, vitreous incrustation. Spe- 
cimens have been found in all stages, even to the complete disappear- 
ance of the corundum ; in the latter instance, a fibrolite pseudomorph 
after corundum remains. 

Kyanite. — The empirical formula of kyanite is uncertain. It is 
regarded by some as a basic orthosilicate, Al 2 3 .Si0 2 , like andalusite 
and sillimanite, while by Groth it is considered a metasilicate, 
(A10) 2 SiO s . It crystallizes in the triclinic system, and is usually 
found in long bladed crystals rarely terminated. The macropina- 
coids or flat blade faces are often striated horizontally. It also 
occurs coarsely bladed, columnar to subfibrous. Cleavage on the 
macropinacoids, very perfect. The hardness varies from 4 to 7.25 
according to direction. Color, blue to white ; blue along center of 
blade with white margin. It also occurs gray, green and black. 

It is often associated with corundum at Litchfield, Newton and 
Washington, Conn. It occurs in large roll masses with corundum 
and massive apatite. In North Carolina, it is found at several cor- 



48 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

undum mines, associated with corundum and muscovite, which, ac- 
cording to Genth, is derived from the alteration of the corundum. 
In Georgia, as an associate of corundum, it is found near Powder 
Springs, Cobb county. 

Tourmaline. — Dr. Smith found tourmaline in great abundance 
with the emery of Naxos, and in less quantities in other localities, 
disseminated through the emery. In the United States, most inter- 
esting specimens have been collected. 

Colonel C. W. Jencks found a pseudomorph of tourmaline after 
corundum at Corundum Hill, N. C. The length and breadth of the 
crystal is about two inches. It shows the planes of the hexagonal 
prisms and portions of one pyramidal plane. Almost the entire crys- 
tal has altered into black tourmaline, leaving only a shell one-fourth 
of an inch thick, while the lower part is mixed with corundum. 
Plates of green chlorite penetrate the crystal. From Unionville, Pa., 
Dr. Isaac Lea mentions a crystal of transparent green tourmaline 
passing through the middle of a prism of diaspore, the whole en- 
veloped by lamellar crystals of pearly muscovite. The associate 
tourmaline of corundum is commonly black. The triangular prism 
predominating, it is readily distinguished from common black horn- 
blende, which it resembles somewhat closely, by examining a cross- 
section of the crystal, which is either three, six or nine sided. It 
has a strong tendency toward crystallization ; hence crystals, usually 
prismatic in habit and often slender to acicular, are very common. 
The prismatic faces are very strongly striated, vertically, often giving 
a rounded appearance to the crystals. The crystals frequently 
occur alone, but often in parallel and radiating groups. A columnar 
and black variety is often confused with common hornblende; but its 
lack of cleavage and its coal-like appearance on a broken surface aid 
in distinguishing it. Tourmaline is almost wanting in cleavage, and 
is brittle even to friable. The hardness is 7.5. Its chemical formula 
is uncertain. Tourmaline is a complex silicate of boron and alumi- 
num, with either magnesium, iron or the alkali metals prominent. 
Tourmaline has been found in Georgia, at the Laurel Creek corun- 
dum mine, Rabun county, and at the Hog Creek corundum mine, 
near Hiawassee, Towns county. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 49 

Staurolite. — This mineral usually occurs in cruciform twins; 
and, on this account it has been much worn as an amulet. Just at 
this time, it is quite the fashion to carry small twin crystals of stau- 
rolite in the pocket, and call them "good luck stones." The crys- 
tals are orthorhombic; they have distinct, but interrupted, cleavage, 
parallel to the brachypinacoid ; they are brittle, and have a sub- 
conchoidal fracture. In color, staurolite is dark reddish-brown to 
brownish-black; and in diaphaneity, it varies from translucent 
to nearly opaque. Its hardness is 7 to 7.5 ; and its specific 
gravity, from 3.65 to 3.75. The chemical formula is HAl 5 FeSi 2 13 , 
in which the Aluminum is partly replaced by ferric iron, and the 
ferrous iron by magnesium and manganese. Genth analyzed a few 
minute massive brown grains of a mineral associated with dam- 
ourite, and resulting from the alteration of corundum, at the Co- 
rundum Hill mine, Macon county, N. C, and found them to be 
staurolite. The specific gravity was 3.71 1. 

HYDROUS SILICATES. 

Micaceous Minerals. 
The micaceous minerals, associated with corundum, will be con- 
sidered in the following order, viz: — 

1. Micas. 

2. Clintonites. 

3. Chlorites. 

4. Vermiculites. 

The micas include the micas proper, that is, those micaceous 
minerals, characterized by a highly perfect basal cleavage, yielding 
very thin, tough and more or less elastic laminas. Clintonites, or 
the brittle micas, form a transition between micas and chlorites* 
They include those micaceous minerals, which are near the micas 
in cleavage, crystalline form and optical properties, but which differ 
from them physically, in the brittleness of the laminae, and chem- 
ically, in their basic character. The chlorites include a large number 
of ferrous magnesium-aluminum silicates of micaceous character, 
but whose laminas are tough and comparatively inelastic. They 
are usually green in color, and hence are called chlorites. The ver- 
miculites form a supplementary group, being chiefly hydrated com- 



50 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

pounds, resulting from the alteration of the micas. They are, in 
part, closely related to the chlorites; but they vary from the chlo- 
rites somewhat widely in composition. 

All these species are characterized by their highly perfect basal 
cleavage; and they yield easily thin laminas. They all crystallize in 
the monoclinic system, and imitate so closely hexagonal or rhombohe- 
dral symmetry, that it is only within the last few years, that their 
true symmetry has been recognized. They are more or less closely 
related in the angles of prominent faces. They are classed as hy- 
drous silicates, but not strictly, since the water they yield upon 
ignition may be regarded, probably in all cases, as water of con- 
stitution. 

MICAS. 

Phlogopite, Muscovite (Damourite, Ephesite, Lesleyite), Paragonite 
(Euphyllite.) 

Phlogopite. — A magnesian mica, especially characteristic of 
serpentinous formations. The crystals are often large and coarse, 
usually only six-sided prisms, more or less tapering, with irregular 
sides. Cleavage, highly eminent; laminas, tough and elastic. 
Hardness, 2.5 to 3; specific gravity, 2.78 to 2.85. Its color is yel- 
lowish-brown to brownish-red; also pale brownish-yellow, green, 
white and colorless. It is commonly present in chrysolite forma- 
tions. Beautiful small crystals have been found in the Laurel 
Creek corundum mines, Rabun county; and, in 1889, large quanti- 
ties of a heavy, foliated kind, intimately associated with a massive 
asparagus-green apatite, w r ere taken from one of these mines. 
Analysis, in the laboratory of the U. S. Geological Survey, showed 
that this phlogopite had begun alteration to a vermiculite. 

Muscovite (Damourite). — Damourite, for a long time supposed 
to be a distinct species, was proved by Dr. Genth, six or eight 
years ago, to be muscovite. Under damourite, as a variety, are 
included, in the last edition of Dana's System of Mineralogy, mar- 
garodite, gilbertite, hydro-muscovite and most hydro-mica in gen- 
eral. The foliae are less elastic than muscovite; the luster is some- 
what pearly or silky; and they feel unctious like talc. The scales 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 5 1 

are usually small; but it passes into forms, which are fine scaly or 
fibrous, as sericite, and finally into a compact crypto-crystalline 
form. It is often derived by alteration from kyanite, topaz and 
corundum. 

Damourite is one of the most important alteration products of co- 
rundum. It may be formed, by direct alteration of corundum, or 
from some of its changed conditions. Besides this, it varies so in 
appearance, that surety of correct diagnosis necessitates a chemical 
analysis. The manifold nature of damourite is shown in the dissem- 
ination of the mineral as pseudomorphs after silicates. Dr. Genth 
notices pseudomorphs after corundum from Unionville, Chester 
county, Pa., from North Carolina, and from Laurens county, S. C. 

Ephesite and Lesleyite. — Dr. J. Lawrence Smith l first noticed 
the former of these from Gumuch-dagh, and gave it the name 
ephesite, because of its occurrence near the ancient city of Ephesus. 
This is a mechanicalmixture of corundum and damourite, or the 
result of an almost complete alteration of corundum into fibrolite and 
the subsequent alteration of the latter into damourite. Dr. Isaac Lea 
called a similar mixture from Unionville, Pa., lesleyite, not observ- 
ing, that the material was a mixture of two minerals. This mineral 
substance, according to Dr. Smith, resembles white kyanite of lamel- 
lar structure. Dr. Genth describes lesleyite as fibrous and com- 
pact, fibrous-columnar, fibrous and divergent, with a grayish-white 
color to reddish, depending on the presence of iron. The hardness 
is given at from 4 to 7. 

Paragonite. — This is a soda mica, corresponding to muscovite 
in composition. It commonly forms a mass of rock, containing 
kyanite, staurolite, garnet and tourmaline, called paragonite schist. 
Its association, in Saxony and elsewhere, with corundum, leads 
Genth to ask, if these paragonite schists may not be the result of 
the alteration of corundum passing through the stage of fibrolite 
and damourite. 

Euphyllite. — This is a sodium-potassium mica, apparently in- 
termediate between muscovite and paragonite, but more basic. It 
is a rare associate of corundum at Unionville, Pa. 

1 Amer. Jour. Sci. (II) 59, 1851. 48, p. 254, 1869. 



52 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

CLINTONITES. 

Mar g arite, Chloritoid. 

Margarite. — Its name is derived from the Greek word for pearl. 
It is characterized by a pearly luster on a cleavage face. Its 
hardness is 3.5 to 4.5, and its specific gravity varies from 2.99 to 
3.08. In color, it is grayish-white, pink or yellowish. It is com- 
monly associated with corundum, and in many cases is obviously 
formed directly from it. Smith and Silliman discovered it, almost 
simultaneously, in Asia Minor and Greece, and in Pennsylvania 
and South Carolina respectively. Since then, it has been discovered 
in many corundum localities ; but, on account of certain forms of 
damourite, which resemble it closely, an analysis is necessary to pre- 
vent confusion. An analysis of this mineral from Gainesville will 
be found on page 99. 

Chloritoid. — Chloritoid has been found in many corundum lo- 
calities. It was noticed by Smith to be in abundance with the emery 
of Gumuch-dagh, covering the surface of emery blocks, and some- 
times entering largely into the substance of the emery. From this, 
it was very apparent to him, thatitwas formed by elimination from 
the mass of emery at the time of its consolidation. 

The crystals are grouped in rosettes. When massive, which is 
its usual habit, the folias are coarse and often bent or curved, and 
brittle. Its hardness is 6.5, and its specific gravity, 3.52 to 3. 57» 
In color it is dark-gray, greenish-gray, greenish-black and grayish- 
black. 

CHLORITES. 

Prochlorite, Corundophilite. 

Strict lines of division between the chlorites is extremely diffi- 
cult, and a correct interpretation of their composition is equally so, 
neither having, as yet, been satisfactorily accomplished. Chem- 
ically considered, the chlorites are silicates of aluminum, ferrous 
iron and magnesium, chemically combined with water. Chromium 
may be present in small amount, replacing a part of the aluminum, 
in which case, the color is pink instead of the common green. 
Ferric iron is also sometimes present, replacing a part of the alu- 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 53 

minum. Calcium and the alkalies, characteristic of all true micas, 
may be present in small amounts ; but they are usually conspicuous 
by their absence. The chlorites, which are about to be described, 
belong to a distinct series, showing a constant percentage of water, 
and a decrease of silica, magnesia and ferrous iron, accompa- 
nied by an increase in aluminum. Since, however, it is impossible 
to distinguish them, except by chemical analysis, the varieties, 
which have been found associated with corundum, will be consid- 
ered together. 

Prochlorite, Corundophilite. — Externally, these two chlorites 
are indistinguishable. Both are monoclinic, and occur, either as 
six-sided tables or low prisms, or massive, foliated or granular. 
Both possess the same color, viz., green, grass-green, olive-green, 
blackish-green. In the case of prochlorite, the lamina? are simply 
flexible, while corundophilite laminae are somewhat elastic. 

Varieties of these, not too near the division line, will present 
certain optical differences. Chemical analysis, therefore, is abso- 
lutely necessary for a safe determination of these species . As has 
been said previously, an increase in alumina will show a decrease 
in silica, magnesia and ferrous iron. Corundophilite, therefore, can 
be distinguished from prochlorite, by its possessing more alumina 
and less silica, ferrous iron and magnesia. Prochlorite usually has 
a large amount of ferrous iron ; but analyses of the prochlorite 
found associated with corundum at Corundum Hill, North Carolina, 
show only a small percentage. 

THE VERMICULITES. 

Jefferisite, Culsageeite, Kerrite, Lucasite, Painterite, Maconite, Dud- 

leyite, Willcoxite. 

The vermiculite group represents a large number of micaceous 
minerals, which, in the main, are alteration products of the micas. 
They are closely related to the chlorites ; but they vary from them 
somewhat widely in composition. Many of them have a more or 
less indefinite chemical nature, varying with the degree of altera- 
tion of the original minerals. The laminse may be said, in general, 
to be soft, pliable and inelastic ; the luster is pearly or bronze-like, 



54 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 

according to color, which varies from white, through shades of 
yellow, to brown. Dried over sulphuric acid, or heated at from 
ioo° to no° C, they lose, up to ten per cent, of water ; at 300 , 
more water is given off, and, at red heat, a somewhat large propor- 
tion is given off. This drying process leads to the common phys- 
ical character of exfoliation, which is common to nearly, if not all, 
the vermiculites, causing them to expand, when heated, into worm- 
like threads. This physical change caused the name vermiculite 
to be given to the oldest member of the group, from the Latin, 
ve7*miculari, to breed worms. 

Vermiculites are extremely common in corundum veins, in some 
instances forming the complete gangue for the mineral. This is 
instanced at the Corundum Hill mine, North Carolina, where 
Chatard 1 speaks of a so-called "sand-vein," made up of a vein-like 
mass of brown vermiculites, containing an abundance of small 
corundum crystals. Again, in his sections: — In section A, he finds 
a six-inch seam of vermiculites ; in Section B, twelve inches of fine, 
scary, brown vermiculite; and in section C, a six-inch streak of ver- 
miculite. Vermiculites also play a prominent part in the corundum 
veins of the Laurel Creek mine, and certain other corundum 
localities of Georgia. 

Jefferisite (Culsageeite.) — The culsageeite variety of jeffer- 
isite comes from Corundum Hill mine, near Cullasagee Post-office, 
N. C. It consists of broad crystalline plates, of eminent cleavage 
and pearly luster. The color is yellowish-brown to brownish-yel- 
low. It shows very well the characteristic of exfoliation on heat- 
ing. Here, it is formed from the alteration of a chlorite, which 
very frequently shows an incipient alteration to this mineral, by a 
discoloration to brown or brownish-yellow. 

Kerrite. — Kerrite was named by Dr. Genth, in honor of the late 
Professor W. C. Kerr, State Geologist of North Carolina. It con- 
sists of innumerable fine scales, which, under the microscope, pre- 
sent no definite shape. Its color is pale greenish-yellow with a tint 
of brown, and its luster is pearly. It does not exfoliate as readily 
as jefferisite. 

1 Bui. 42, IT. S. Geol. Survev, T. M. Chatard. 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 55 

Lucasite. — This mineral was found to be a new vermiculite 
species, by Dr. T. M. Chatard, who discovered and analyzed it. 
He named it for Dr. H. S. Lucas, who has been such an indefa- 
tigable worker, in developing the corundum deposits of Georgia 
and North Carolina. This vermiculite occurs with actinolite at 
Corundum Hill, N. C. The folias are small, compact and dissemi- 
nated; and they exfoliate largely on ignition. It is easily decom- 
posed by hydrochloric acid. 

Painterite. — This vermiculite occurs at the Corundum mine 
in Newlin township, Chester county, Penn., as a dull green mineral; 
and, as a golden-yellow mineral, it is found on the farm of James 
Painter, Middletown, Delaware county, Penn., for whom it was 
named. In the former color, it much resembles culsageeite, both 
outwardly and optically. 

M aconite. — This species discovered by Genth, closely resem- 
bles fine scaly jefrerisite. The scales are harder than kerrite, and 
are irregular. It exfoliates largely upon heating, and fuses with 
difficulty to a brown glass. It is easily decomposed by hydro- 
chloric acid, with a separation of silica in scales. 

Dudleyite — This vermiculite is an alteration product of mar- 
garite. It is found in large quantities at Dudleyville, Ala. Genth 
describes it, as a soft bronze or brownish-yellow mineral, which 
still retains the form and pearly luster of margarite. When heated, 
it exfoliates very slightly, and melts with difficulty into a brownish- 
yellow blebby mass. It decomposes easily in hydrochloric acid, 
with the separation of silica in pearly scales. This mineral is also 
found in the North Carolina corundum regions. 

Willcoxite. — This was named by Genth for Colonel Joseph 
Willcox of Philadelphia, Penn., the well known amateur collector 
of American minerals and fossils. It occurs as a coating around a 
nucleus of corundum, and is presumed to be an alteration of it. It 
occurs at Shooting Creek and Cullakenee Mines, Clay county, 
N. C. The scales are white to greenish or grayish-white, with 
pearly lustre, resembling talc. Before the blow-pipe, in thin 
splinters, it fuses with difficulty into a white enamel, coloring the 
outer flame yellow. It decomposes with difficulty in hydrochloric 
acid, with the separation of silica in pearly scales. 



$6 ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 
THE SERPENTINE AND TALC GROUP. 

Serpentine, Genthite, Talc. 

This group, containing serpentine and talc, as the leading mem- 
bers, is closely related to the chlorite group. Included with them 
are some amorphous, magnesian silicates, such as genthite. 

Serpentine. — Serpentine crystallizes in the monoclinic system. 
Its composition is that of a hydrous magnesian silicate. Crystals 
of serpentine are sometimes found in the chrysolite rocks, but 
only as pseudomorphs after chrysolite. It is usually massive, 
and occurs in these chrysolite rocks as an alteration pro- 
duct. It also occurs delicately fibrous and silky, in which form it 
is extensively used for asbestus. The color is from yellowish-green 
to blackish-green, and sometimes red and black. Massive serpen- 
tine, more or less pure, frequently occurs as an alteration of chryso- 
lite or pyroxene; but it has not been observed in connection with 
the corundum-bearing magnesian formation of Georgia. The 
chrysolite rocks of these formations are frequently spoken of as 
serpentine, because of their partial serpentinization ; but this is a 
misnomer. 

Genthite. — This amorphous mineral occurs as an apple-green 
or a yellowish incrustation on chromite near the Hog Creek mine, 
Hiawassee, Towns County. It is a hydrous nickel-magnesium 
silicate, with the formula 2Ni0.2Mg0.3Si0 2 .6H 2 = silica 34.8, 
nickel protoxide 28.8, magnesia 15.3, water 20.9=100. In a 
closed tube, submitted to heat, it blackens and gives off water; it 
is infusible before the blow-pipe. When exposed to the air for 
some time, it loses its apple-green color and breaks down into a 
powder. 

Talc. — Talc is either orthorhombic or monoclinic; it usually 
occurs in foliated masses, or granular massive; it is also fibrous or 
compact. When foliated, the f olise are easily separated ; it is soft, 
and has a greasy feel. The foliated variety is known as talc. The 
fine granular and compact varieties are known as soapstone 
or steatite; the very coarse, as pot-stone, because used by the In- 
dians and aborigines of this country for making pots. The fibrous 



ALTERATIONS AND ASSOCIATE MINERALS OF CORUNDUM. 57 

varieties are usually pseudomorphs after pyroxene. All these 
varieties occur in chrysolite formations, and are readily distinguished 
by their softness and greasy feel. 

PHOSPHATES. 

Apatite, Lazulite. 

Apatite. — Apatite is a calcium phosphate, in which either fluo- 
rine or chlorine, or both together, are combined with part of the 
calcium. It crystallizes in the hexagonal system, and has pyramidal 
hemihedrism. Crystals vary from long to short prisms; they also 
occur as low pyramids, slightly modified by prismatic faces. The 
hardness of apatite is from 4.5 to 5, and its specific gravity is from 
3.17 to 3.23. Its cleavage is imperfect, and its fracture uneven. 
It is brittle. Its luster is vitreous, inclining to sub-resinous, and in 
color it is usually sea-green to bluish-green, though it sometimes 
occurs white (opaque and transparent), pink, purple, brown and 
black. 

Two pieces of apatite crystals, one four inches, the other two 
inches in diameter, were given to the Survey, as specimens from 
the Laurel Creek mine. They are sea-green in color and trans- 
parent to translucent. Scales of phlogopite are inclosed by the 
large piece, and it encases parts of both specimens. This is a rare 
associate of corundum, and is not mentioned among the minerals 
of the North Carolina corundum mines. 

Lazulite. — This is essentially an aluminum phosphate, in which 
are present, in varying proportions, magnesia and iron protoxide, 
with water. It crystallizes in the monoclinic system; the crystals 
are usually acute, and sometimes flattened. It also occurs mas- 
sive, granular to compact. Its cleavage is indistinct, and its 
fracture uneven. Its hardness is from 5 to 6, and its specific 
gravity is 3.05. In color, it is azure-blue. It occurs in abundance 
with corundum at Crowder's Mountain, Gaston county, 1ST. C. It 
is not known in Georgia in this association; but beautiful sky-blue 
crystals, over an inch broad and as long, are found at Graves' 
Mountain in Lincoln county. 



CHAPTER IV. 
GEOLOGY OF THE CRYSTALLINE BELT. 

Introduction. , 

Map of Georgia. 

Topography of the Crystalline Belt. 

Structure and Physiography of the Crystalline Belt, and its Evolu- 
tion. 
Age of the Crystalline Belt. 
Geology of the Holo-Crystalline Area. 

INTRODUCTION. 

Introductory to the descriptive chapter on the corundum deposits 
of Georgia, a brief chapter on the geology of the entire so-called 
crystalline area will not be amiss. The mineral resources of any 
region are so dependent upon its geology, that an intelligent view 
of any one of them requires a general knowledge of the age, 
structure, lithology and topography of the region, in which it is 
found. Such are their reciprocal relations, that knowledge of one 
adds to our knowledge of the other. Likewise the liability of 
error in conclusion, in regard to any one subject, decreases in pro- 
portion to the increase of acquaintance with all. 

Notwithstanding the importance of detailed geological informa- 
tion, the crystalline belt has received only the most cursory exam- 
ination. Mapping in detail has been held in abeyance for general 
prospecting. Attention has been confined to the discovery of eco- 
nomic minerals, to the almost complete exclusion of those things 
which would have lent acumen to the search. Hence, many facts 
are wanting for a perfectly satisfactory discussion of the geology 
of this area. Still, a few general statements in regard to the same 
may be found useful. 

MAP OF GEORGIA. 

The last geological map of the entire State was compiled by the 
Agricultural Department in 1885, and may be seen in the report of 
that year. Their data was altogether insufficient for a good map; 
yet, in a rough way, it shows the prominent formations and their 
distribution over the State. 



GEOLOGY OF THE CRYSTALLINE BELT. 



59 



Spencer, in his " First Report of Progress, 1890-91," maps in 
detail the area south of a line drawn from Columbus to Knoxville, 
and west of Flint river. His last report, " Geology of the Pale- 
ozoic Group of Georgia and Resources, 1893," contains a detail 
map of ten of the northwest counties, or the entire northwest 
corner of the State. 

Fig. 4. 




Geological Outline Map of Georgia. 

A, Algonkian ; S, Semi-crystalline ; P, Paleozoic ; M, Mesozoic ; C, Cenozoic - T 
E, Kecent. 



60 GEOLOGY OF THE CRYSTALLINE BELT. 

From these maps, it may be learned that more than one-half of 
the surface area of Georgia is covered by the later formations. 
This area lies south of a line drawn south of west from Augusta, 
Richmond county, to Columbus, Muscogee county ? and is made up 
of Mesozoic, Cenozoic and recent formations. 

The known Paleozoic area of Georgia covers about 3,408 
square miles. In it are represented all the systems of the Pale- 
ozoic, viz.: — Cambrian, Silurian, Devonian and Carboniferous. The 
Devonian, Spencer does not map, because the formation is extremely 
limited, and occurs in valleys; consequently outcroppings are rarely 
seen. A line drawn south from a point a few miles east of Cohutta 
Springs, Murray county, to Cartersville, Bartow county, and then 
south of west to Esom Hill, Polk county, inclosing the northwest 
corner of the State, sharply defines the limits of the Paleozoic in 
Georgia. This is known as the "Cartersville Fault." 

Between these two areas of the State, and occupying the greater 
part of North Georgia, is the so-called " Crystalline Belt," with a 
surface area of about 12,430 square miles. It will be seen, by re- 
ferring to Fig. 4, that this region is divided into a " semi-crystal- 
line " and a " holo-crystalline " area. Explanation of this division 
will be found in a following section of this chapter. 1 The line is 
simply provisional, and makes no attempt at accuracy, leaving 
that to future mapping. The north and south line, however, 
separates the two areas fairly well. Less is known of the east and 
west line. 

TOPOGRAPHY OF THE CRYSTALLINE BELT. 

The surface of the earth presents a figuration and transfigura- 
tion due to natural processes, and " now stands in a transient stage 
between its past and its future." All these changes have been 
brought about by two forces, the one constructive, the other destructive. 

The topography of the Crystalline Belt represents the action of 
these two forces. Great crust movements raised the Appalachian 
system, of which this belt is a part; these were constructive. 
During these periods of uplifting, atmospheric and aqueous agencies 

1 Structure and Physiography of the Crystalline Belt and its Evolution. 



GEOLOGY OF THE CRYSTALLINE BELT. 6 1 

were acting, and have continued to act. These destructive forces 
have sculptured the belt into its present features. 

The Crystalline Belt, on account of its crystalline rocks and com- 
plex structure, presents a more or less diversified topography. 
The southern portion of the belt is broken by low, undulating hills, 
intensified along the large rivers. These elevations increase, as we 
go north. Then come the foot-hills of the Blue Ridge, culminat- 
ing in the Blue Ridge itself, peaks of which, in Georgia, range from 
3,000 to 4,000 feet above the sea-level, the maximum height being 
4,790 feet. This is the highest point in Georgia — Mount Enotah on 
the southwestern side of Towns county. 

The drainage is that, common to all mountainous districts and 
areas approaching sea-level, or " base level," as it is technically 
called. The streams present all stages of activity from youth to 
old age. Tributaries of the Tennessee river drain the belt on the 
north; the south is drained by the Savannah, Ogeechee, Oconee, 
Ocmulgee, Flint and Chattahoochee rivers. 

Before leaving this subject, an individual topographical feature, 
showing the wonderful erosive power of a river, is worthy of men- 
tion — the Tallulah Gorge in the southern part of Rabun county. 
Its superb grandeur, people have traveled far to see; as a geologi- 
cal feature, its fame is world-wide. This narrow gorge is several 
miles long, and nearly a thousand feet deep. 

STRUCTURE AND PHYSIOGRAPHY OF THE CRYS- 
TALLINE BELT, AND ITS EVOLUTION. 

In the consideration of the structure of the Crystalline Belt, with 
a view of interpreting the same, it will be necessary to review briefly 
the structure of Northwest Georgia. North and west of the Crys- 
talline Belt, and occupying the entire northwest corner of Georgia, 
all the systems of the Paleozoic are represented. Erosion, which 
has been actively at work, since the uplifting of the Appalachian 
system, following the Coal epoch, has removed thousands of feet 
of the various formations, and sculptured the area into its pres- 
ent landscape. The general structure of the region, however, is 
mainly consequent upon the faults, overthrows and folding pro- 



62 GEOLOGY OF THE CRYSTALLINE BELT. 

duced by orographic movements. The Paleozoic ceases abruptly, 
on contact with the Crystalline Belt. A gigantic physical break or 
unconformity, which C.W. Hayes has aptly termed "The Carters- 
ville Fault," 1 marks a distinct separation of two regions. The 
structure of the Paleozoic area has been studied in a most careful 
manner by Hayes, Campbell and Spencer, and full particulars may 
be found in Spencer's report on this region, and in the reports and 
atlas sheets of the U. S. Geological Survey, by Dr. C. W. Hayes. 
The structure of the Crystalline Belt has only been studied super- 
ficially, and sufficient scientific examination has not been made to 
warrant more than hypothetical conclusions. In working out the 
detail geology of the Paleozoic, the geologists were in a field much 
less disturbed by dynamic forces, and therefore still containing abun- 
dant paleontological evidence. In the Crystalline Belt, no positive 2 
fossil remains have been found, and the rocks are much more dis- 
turbed and altered. The rocks of the Crystalline Belt are divisible 
into two petrographical classes. The first class consists of a series 
of slate, shale, schist, conglomerate and marble, which, through 
metamorphism, have become more or less crystalline. These un- 
doubtedly are all elastics, and despite their metamorphosed condi- 
tion, preserve, in a measure, evidences of their origin; therefore 
they are classified as semi- crystalline. The second class includes a 
series of granitic, gneissic and schistic rocks, which are thoroughly 
crystalline and without any determinable traces of their origin. The 
latter, therefore, are classified as holo -crystalline. 

The main body of the semi-crystalline rocks of the Crystalline 
Belt is confined to a region bordering on the Paleozoic. Its north- 
western limit is the Cartersville Fault; its southeastern, the begin- 
ning of the " holo-crystalline " rocks. In the small map on p. 59, 
a temporary divisional line has been drawn between these two areas. 

1 C. W. Hayes; Bui. Geol. Soc. Amer, vol. II., p. 147, 1890. 

2 It will be of interest to note the possible fossil, discovered in the marble belt by 
Mr. S. W. McCallie, Asst. State Geologist of Georgia. The specimen was sent to Prof. 
C. D. Walcott, Director of the U. S. Geological Survey, who returned it, saying that 
he was not certain of its character, but thought it might be the fossiliferous remains 
of a gasteropod. 



GEOLOGY OF THE CRYSTALLINE BELT. 63 

It is suggestive, rather than an attempt at accuracy; much more 
work will be required in this section, on account of the nature of the 
transition between them, before the latter can be hoped for; never- 
theless, for present purposes, it is fairly accurate. Included in the 
semi-crystalline area are patches of intrusives, whose structural rela- 
tions to the inclosing elastics have an important bearing on the evo- 
lution of the Crystalline Belt. 

It is noteworthy that throughout the semi -crystalline area, wher- 
ever an intrusive occurs, the contact elastics show indubitable evi- 
dences of metamorphism. A single instance will be cited, because 
of its interesting nature and its proximity to the holo-crystalline 
rocks. Near the Tate marble quarries, Pickens county, McCallie x 
observed that apophyses run out from an eruptive basic mass close 
by, and overlap the marble at several points. The accompany- 
ing plate 2 shows one of these veins, intruded between gneiss and 
marble. The result of this contact was evidently the conversion of 
a clastic into a gneiss, and important physical changes in the marble, 
the most interesting and noticeable of which was the expulsion of 
the coloring matter, so common in Georgia marble. McCallie 
found that this was true of every similar occurrence. 

Principally, the rocks of the semi-crystalline area are mica-schists, 
usually soft, and bedded slates. All dip to the southeast, and strike 
about 20 degrees west of south. The dip ranges from 15 ° to 6o°, 
with an average dip of about 30 . 

To the southeast of the semi-crystaliine area, and transitional 
with its formation, lie the holo-crystalline rocks. Gneiss is the pre- 
vailing type. Interstratified with the gneiss, in certain portions of 
this area, a few beds of semi-crystalline rocks have been observed, 
such as the belt of limestone running through Habersham and Hall 
counties, the quartzite of Tallulah Gorge, and the phyllites of 
Lumpkin county. Breaking through the holo-crystalline rocks, a 
belt of outcroppings of basic magnesian silicates, containing the 
corundum of Georgia, extends from North Carolina through Geor- 

1 See Bulletin No. 1, Geological Survey of Georgia; The Marbles of Georgia, by 
S. W. McCallie, p. 40. 
2 See Plate II. 



64 GEOLOGY OF THE CRYSTALLINE BELT. 

gia into Alabama. These eruptive masses are most numerous west 
of the Chattahoochee river, close up to the "semi-crystalline"" 
line. Although some are found east of the river, as far as Monroe, 
Walton county, none occur in the semi-crystalline area. These 
physiological facts are significant in the study of the evolution of 
the Crystalline Belt. The presence of elastics among holo-crystal- 
line rocks tends to confuse the opinion, that this area represents the 
fundamental complex. The disappearance of these corundum- 
bearing formations points to a time of deposition of the semi-crys- 
talline rocks, later than these intrusions, while their continuity along 
a definite belt is suggestive of the force and direction of the great 
earth movement, that developed this line of weakness and permitted 
the welling up of so much igneous matter. 

The strike of the holo-crystalline area corresponds with that of 
the semi-crystalline ; but the dip is on an average much steeper and 
may be given as about 50 . Moreover, disturbances and altera- 
tions are more extensive in this region, than in the semi-crystalline. 
The sharp folds and faults, which must exist in such a folded area, 
are no longer noticeable. Rocks have changed their physical char- 
acter ; for instance, diorite has taken on a gneissoid structure ; 
slates have changed into phyllites (mica-slates), and the mica-schists 
are harder than those of the semi-crystalline area. Even local 
metamorphism, consequent upon igneous intrusions, so noticeable 
in the semi-crystalline rocks, is little, if at all, apparent in the holo- 
crystalline rocks. 

The apparent constancy of dip to the southeast throughout the 
whole Crystalline Belt is one of the most interesting structural fea- 
tures of the region. It shows, almost conclusively, that the entire 
area has been affected by a great orographic movement, the ob- 
jective point of whose force was to the northwest, or at right 
angles to the present strike of the rocks. There can be little doubt, 
also, from the structural and physiological features of the Crystal- 
line Belt, but that the force exerted its influence over a long period 
of time. The complex structure thus produced, erosion has effaced 
into a deceitful simplicity, that will always be a source of trouble to 
the economic worker. He must guard against taking, as the real 



GEOLOGY OF THE CRYSTALLINE BELT. 



65 



thickness of a formation, the measurement of its horizontal extent; 
for what appears as one bed, now that general erosion has removed 
the original surface, is in reality often a succession of beds. The 
complexity, moreover, is increased by metamorphism and superfi- 
cial decay, which have wiped out, in a great measure, structural 
lines and similar evidences pointing toward sequence relations. 
These facts are brought out in the following figure : — 

Fig. 5. 




Ideal geological section, showing the degradation of the tops of folds, and the direc- 
tion of the force producing them. 

This figure serves, also, to illustrate the method of determining 
the direction of force in simple earth movements. The longer slope 
of the fold is always toward the moving force ; and, after erosion 
has removed the tops of the folds, only the longer slope remains, as 
the dip of the strata. 

The structural features, which have been noted, may then be 
briefly summarized as follows : — 

1. The " Cartersville Fault," which marks a time interval be- 
tween the deposition of the semi-crystalline rocks of the Crystal- 
line Belt and the Oostanaula Shales of the Paleozoic. 

2. The apparent perfect transition between the semi-crystalline 
and the holo-crystalline rocks. 

3. The absence, in the semi-crystalline area, of the magnesium- 
corundum deposition, which characterizes the holo-crystalline area. 

4. The constancy of strike and dip of the rocks of the semi- 
crystalline and holo-crystalline areas. 



66 



GEOLOGY OF THE CRYSTALLINE BELT. 



5. The difference in degree of dip between the rocks of the 
semi-crystalline and holo-crystalline areas. 

6. The absence of regional metamorphism in the eruptive por- 
tions of the holo-crystalline area, and its presence in the semi-crys- 
talline. 

7. The evidence, which testifies to an earth movement, preced- 
ing, and a continuous earth movement, following the deposition of 
the rocks of the semi-crystalline area. 

From these observations on the structure of the Crystalline Belt, 
three hypotheses present themselves, viz.: — 

1. That the semi-crystalline area is of the same age as the con- 
tact member of the Paleozoic, and that the holo-crystalline area is 
Archaean. 

2. That the Crystalline Belt is older, than the contact member of 
the Paleozoic; that the divisions of the belt are of the same age; 
and that the holo-crystalline has the appearance of greater age* 
because of extreme metamorphism, brought about by igneous in- 
jections and concentrated dynamic forces. 

3. That the semi-crystalline area is older than any member of the 
Paleozoic known in Georgia; that the corundum-bearing magne- 
sian eruptives, were intruded prior to the deposition of the rocks 
of the semi-crystalline area; and that the holo-crystalline rocks 
formed a sea-floor for the deposition of the semi-crystalline. 

The first two hypotheses do not conform to facts; but they are 
given, because they seem current. 

The first hypothesis presumes to give an age to both areas; these 
ages, however, are at variance with the facts. The first fails to 
appreciate the Cartersville Fault, which represents an unmistakable 
time interval, because no cause could probably alter one part of an 
original series more than another, and produce such a great uncon- 
formity. The semi-crystalline area is evidently older than the 
Oostanaula shales. Again, in ascribing Archaean age to the holo- 
crystalline, present terminolog} 7 * is undoubtedly violated. 

The second hypothesis notices the time-break represented by the 
Cartersville Fault; but it does not permit of any interval between 

1 See Age of Crystalline Belt, p. 67. 



GEOLOGY OF THE CRYSTALLINE BELT. 67 

the formation of the semi-crystalline and the holo-crystalline areas. It 
accounts for the difference of rock-character, by metamorphism, 
brought about by eruptives and dynamic forces. The seemingly 
perfect transition between the two areas tends to support the valid- 
ity of this hypothesis. Opposed to it, however, is the disappear- 
ance of the corundum depositories at the semi-crystalline line ; also, 
that lateral pressure from one direction, as shown by the strike and 
dip of the rocks, could have been sufficiently concentrated in one of 
the contiguous areas, to have removed evidences of contact meta- 
morphism in one area and not in the other, especially at points close 
to each other. 

Finally we are reduced to the third hypothesis, which presents 
conclusions more in accord with known facts, and may be held pro- 
visionally, until modified by later investigations. This views the 
Crystalline Belt as two distinct areas in point of age, and older 
than any other formations in Georgia. It considers the waters of 
the semi-crystalline sea to have washed the shores of a holo-crys- 
talline continent already impregnated by the magnesian eruptives, 
in which we find deposits of corundum; and, further, that, at the 
time of the final uplifting of the semi-crystalline area, its forma- 
tions, resting on the holo-crystalline sea-floor, which was being 
crushed and raised by the great orographic movement, were re- 
acted upon, and the present sharp folding and faulting of the semi- 
crystalline area resulted. 

AGE OF THE CRYSTALLINE BELT. 

A conjectural age is still given to the rocks of this belt. Dr. 
Little, 1 State Geologist of Georgia, from 1874 to I ^79? considered 
the whole area metamorphosed Lower Silurian. Dr. Spencer, in 
his last report, 2 maps the rocks of the Crystalline Belt, in contact 
with the Oostanaula shale of the Paleozoic, as metamorphic, and 
refers to them as questionably Lower Cambrian. The remainder 
of the belt he calls Archaean. Campbell and Ruffner 3 considered 

1 George Little, Keport of Ga. Geol. Sur., 1876. 

2 J. W. Spencer, Geol. Paleozoic Group of Ga., 1893. 

3 A Physical Survey, extending from Atlanta, Georgia, across Alabama and Missis- 
sippi to the Mississippi River, along the line of the Georgia Pacific Railway, by 
J. L. Campbell and W. H. Ruffner, New York, 1883, p. 147. 



68 



GEOLOGY OF THE CRYSTALLINE BELT 



the portion examined by them as Archaean, and distinguished the 
two divisions, Laurentian and Huronian. Since, however, no par- 
ticular scientific examination of the area was made by any of these 
workers, except in detached areas, their statements may be taken 
as simply expressions of opinion, and not verified conclusions. 

On the eastern slope of the Appalachian System, undoubted 
patches of Archaean rocks extend as far south as Virginia, and our 
geologies generally run them into Georgia. 

With such data, the geological map of Georgia was compiled by 
the Agricultural Department in 1885; and thus the entire Crystal- 
line Belt appears on the " legend " as Archaean. This, therefore, 
does not accord with any opinion, thus far expressed. 

The prevailing opinion seems to be, that the Crystalline Belt is 
composed of rocks of at least two ages. The preceding section of 
this chapter coincides with this view. All the geologists, who have 
worked in the neighborhood of the Cartersville Fault, agree, that 
the rocks of the Crystalline Belt in that vicinity are metamorphosed 
elastics; and, if we may go so far as to infer it from their writings, 
they consider them of the Lower Cambrian. Until, however, 
more evidence is obtained to substantiate this age, which is 
probably correct, they may more properly be assigned to another 
period. 

The greater portion of the Crystalline Belt, or what is here 
termed the holo- crystalline area, has been considered Archaean. 

What rocks may be called Archaean ? 

Professor Van Hise, authority on Pre-Cambrian geology, in his ex- 
haustive correlation bulletin, gives the following answer: 1 — " The 
Archaean is the basal complex of America. It has everywhere, if 
large areas are considered, an essential likeness. It consists 
mainly of granitic, gneissic and schistic rocks, among which are 
never found beds of quartzite, limestone or other indubitable 
elastics." He further adds, that their structural relations and the 
character of the rocks themselves show, that they have passed 
through repeated powerful dynamic movements. 

1 C. K. Van Hise, Correlation Papers — Archaean and Algonkian. Bui. U. S. G. S. 
No. 86, p. 13. 



GEOLOGY OF THE CRYSTALLINE BELT. 69 

In the holo-crystalline area of the Crystalline Belt, are found, as 
cited 1 in the preceding section of this chapter, what Professor Van 
Hise would consider " indubitable elastics." If Professor Van 
Hise's definition of Archaean is accepted, the presence of such rocks 
in this area renders the assignment of Archaean age out of the ques- 
tion; and, if not, it at least makes this term objectionable, until bet- 
ter defined. 

What age, therefore, can we properly assign to these two areas 
of the Crystalline Belt? 

Rocks, heretofore, which, on account of their apparent clastic 
nature, could not be called Archaean, have been classified as Pre- 
Cambrian. American geologists now embrace the Pre-Cambrian 
elastics and their crystalline equivalents, under Algonkian. The 
Algonkian is limited, below, by the Archaean, and above, by the 
Cambrian. Sharp lines of demarcation are frequently impossible. 
Age has a tendency toward greater changes; nevertheless, re- 
moved regions of the same age may be unequally affected. In 
several areas, unconformities or structural breaks can be readily 
determined, while, in others, these distinct lines between the series 
will have been entirely wiped away, by metamorphosing influences. 
In this difficulty of differentiation, however, the Algonkian system 
is in no way different from other systems. In this period, we find 
time breaks, as in the others. 

For these reasons, therefore, as an expression of our present 
knowledge, this entire complex Crystalline Belt may be provision- 
ally assigned to the Algonkian period. Thus assigned, we are no 
longer involved in the absurdity of including known elastics in the 
Archaean; neither, if we have overlapped the Archaean or the Cam- 
brian, have we done violence to our terminology, 

1 See pages 63 and 64. 



7o 



GEOLOGY OF THE CRYSTALLINE BELT. 



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GEOLOGY OF THE CRYSTALLINE BELT. 7 1 

GEOLOGY OF THE HOLO-CRYSTALLINE AREA. 

The various rock formations, composing the Holo-Crystalline 
area, cross Georgia from the southwestern corner of North Caro- 
lina and the northwest side of South Carolina, and pass into 
Alabama about midway of the Georgia boundary, moving in a 
general southwest direction. Their course is practically straight, 
the strike being on an average 35 west of south. The dip is 
sometimes vertical; but generally it is sharply inclined to the 
southeast. In a measure, the structural features of the area con- 
form to those of the Appalachian system; but the effacement of 
structural lines in many instances, their complexity, and extreme 
metamorphosed condition strengthens the opinion, that they have 
been subjected to late disturbances. 

The rocks, thus far observed as making up the formations of 
the Holo-Crystalline Area, may be divided into eight distinct types. 
Three of these types, limestone, quartzite and slate, are indubitable 
elastics. Three of them are completely crystalline, namely, 
granite, gneiss and schist, and therefore exhibit no trace of clastic 
origin. Two are presumably of eruptive origin, and may be 
designated, according to their chemical and mineralogical composi- 
tion, as peridotite and metamorphosed diorite or hornblende- 
gneiss. 

The age of these rocks has been discussed in the preceding sec- 
tion of this chapter, and they have been assigned provisionally to 
the Algonkian. As was intimated, however, it is not impossible, 
that more thorough examination of this area will result in assigning 
a portion of it to the Archasan. 

The prevailing rocks are gneiss and mica-schist. The mapping 
of these will require careful work, because of their alternating na- 
ture and easy transition from one to the other. The true bedding 
of these rocks has been more or less obliterated, and the existing 
structure is probably due to secondary foliation. 

The youngest of these Algonkian crystallines are the eruptive. 
The peridotite type, which here includes the chrysolite and its 
alterations, steatite (soapstone), chlorite etc., is quite abundant in 
certain portions of this area. 



72 



GEOLOGY OF THE CRYSTALLINE BELT. 



These basic magnesian silicates sometimes occur in large masses; 
but they are usually found in Georgia, occupying small areas. 
Frequently, as elliptical-formed bodies, they stretch out several 
miles across the State, like a string of beads, with here and there 
a missing member. These are the formations, that are prospected 
for corundum. 

It remains finally to speak of the intrusive (?) diorite or gneiss- 
oid hornblende. This type has been classified in this section as 
an eruptive; but sufficient proof has not been obtained to make it 
more than a probable assertion. It consists frequently simply of 
hornblende, usually with garnets; often it is feldspathic. The 
formations, if intrusive, are narrow dykes, stretching for miles across 
the country, and conforming to its general structure. Since their 
intrusion, they have been squeezed and folded, until now they pre- 
sent the characteristic gneissic structure. The breaking down of 
these dykes, consequent upon erosion, has spread the rotted mate- 
rial far beyond its boundaries, and hence gives rise to many of the so- 
called "red lands" of certain sections. 






CHAPTER V. 
DISTRIBUTION OF CORUNDUM IN GEORGIA. 

Position of the Corundum-bearing Formations. 

Geological Relations of the Corundum-Bearing Formations. 

Corundum Veins. 

Varieties of Corundum Found. 

Description of Localities. 

Origin of Georgia Corundum. 

POSITION OF THE CORUNDUM-BEARING 
FORMATIONS. 

The corundum deposits of Georgia are thought of, as lying with- 
in a narrow belt, whose width, as it enters Georgia from North 
Carolina, is limited to the region between the Laurel Creek corun- 
dum mine, Rabun county, and Brasstown Creek valley, Towns 
county. This represents a distance, east and west, of about 
forty miles. The belt is supposed to narrow down, and enter Ala- 
bama from Troup county. 

The finding of corundum in North Carolina, Georgia and Ala- 
bama, about the same time, led those, who understood the trend of 
the rock formation of this region, to the natural conclusion, that 
there must be a continuous belt of corundum deposits extending 
through the State. Prospectors in Georgia, therefore, scarcely 
stepped out of this belt in their search. Their efforts, however, 
south of the mountains, were spasmodic, the depth of superficial 
disintegration making work difficult and unsatisfactory. In the 
mountainous counties, Towns, Rabun and Habersham, where the 
barrier to easy prospecting is at a minimum, the prospectors have 
confined the greater portion of their work. The boundaries of 
this zone have therefore been more or less mythical, especially 
south of the mountains. 

With this knowledge to begin with, time not permitting of much 
detail work, the field season was spent in the so-called "corundum 
belt" and the adjoining territory, covering an area of 4,000 square 



74 DISTRIBUTION OF CORUNDUM IN GEORGIA. 

miles. Results of the work show, that the corundum zone has 
been too narrowly limited, and that it is by no means confined en- 
tirely to the mountainous district. 

GEOLOGICAL RELATIONS OF THE CORUNDUM- 
BEARING FORMATIONS. 

All the corundum deposits, thus far observed in Georgia, occur 
in basic magnesian rocks, whose type has been given as peridotite, 
including chrysolite, anthophyllite, serpentinized chrysolites, 1 schis- 
tose chlorite and steatite or soapstone. These form igneous 
intrusions along the stratification lines of the holo-crystalline rocks, 
the gneiss and schist showing by existing characteristics, that they 
were distended prior to the final folding of this region, and probably 
at a time, when the beds of these crystalline rocks were made a 
portion of the continent. The great earth movement, that uplifted 
the area, developed lines of weakness and cracks. These wounds 
nature healed, by an injection of igneous matter. A portion of 
the rents, thus produced and healed, now form the basic magnesian 
silicates, in which the corundum deposits occur. Earth move- 
ments, since, have concealed, in a great measure, the metamorphic 
influences of this molten material, and have likewise folded some of 
the peridotite alterations into corresponding relations with the schist 
and gneiss. 

A matter of note is the constant presence of hornblende-gneiss, 
either on one side or the other of these formations. Such 
being the case, and since these gneissic-hornblende formations, va- 
rying from fifty to three hundred feet and more in width, are con- 
tinuous for miles across the country, they act as an excellent guide 
in a search for the corundum-bearing formations. Gneiss or mica- 
schist seems always to surround the peridotites, or " chrysolite for- 
mations," as they are commonly called, the hornblende-gneiss 2 ap- 
parently never coming in close contact with the peridotites. 

1 A perfect serpentine has not been seen in any of the corundum formations of 
Georgia. 
2 See map of Laurel Creek mine, page 79. 



DISTRIBUTION OF CORUNDUM IN GEORGIA. 75 

CORUNDUM VEINS. 

The Georgia corundum occurs in veins intersecting the perido- 
tites and their alterations. Sometimes it occurs in the contact bod- 
ies, that is, in the gneiss, mica-schist or hornblende-gneiss; such an 
occurrence, however, has not been observed in Georgia. The 
veins vary in form, from those having practically parallel walls 
(usually inclined and descending to unknown depths) to simply lentic- 
ular pockets. In width, they have been found from one to twelve feet. 

The matrix of these veins differs, not only in different, but in the 
same, localities. These four types have been noticed, viz: — 

i. Lime-soda feldspar, with quartz and phlogopite ; also with 
vermiculites, instead of phlogopite. 

2. Lime-soda feldspar, with actinolite. 

3. A course-grained aggregate of lime-soda feldspar and a black 
hornblende. Margarite is sometimes present in place of the feldspar. 

4. A massive vein made up of a light grass-green amphibole 
(smaragdite), lime-soda feldspar and a little chromite. 

All these types have their walls of compact, scaly chlorite, which 
quite frequently contain corundum. The first type is the most com- 
mon; and, scattered through it, or, as is usual in the case of small co- 
rundum, in "bunches" or "pockets," occur the various colored varie- 
ties of corundum. In such veins, also, immense specimens of mas- 
sive corundum are found. 

The second type is apparently rare. In this, only small, irregu- 
lar pieces of corundum have been found, and these usually possess 
an outer zone of some alteration (?) product of the corundum, 
usually margarite. 

The third type is more common than the second; but it differs 
from the first two in its massive, pegmatitic character, and in its 
hardness. The feldspar and hornblende are both apparently little 
altered, and are about equally proportionate. Gray, grayish-blue, 
and slightly pink corundum are evenly distributed through the mass 
in irregular grains, varying from the size of a pea to several inches 
in diameter. Margarite has been observed in such veins, largely 
developed. 



7 6 DISTRIBUTION OF CORUNDUM IN GEORGIA. 

The fourth type is very rare. It is known only at one property 
in Georgia, and only at a few localities in North Carolina. The rock 
is made up of fine blades of smaragdite, of a beautiful light grass- 
green shade, feldspar, and small grains of pink and ruby-red corun- 
dum, profusely scattered through the mass. In Clay county, N. C, 
beautiful pink corundum occurs in the smaragdite, as veins, from a 
half inch to two and a half inches in thickness, sometimes with a 
slight coating of the lime-soda feldspar. On account of their beauty, 
these are highly prized as mineral specimens, the contrast of the 
ruby-red and the brilliant green being decidedly striking. 

VARIETIES OF CORUNDUM FOUND IN GEORGIA. 

All the varieties of corundum have been found in Georgia, with 
the single exception of emery. The principal is the variety, corun- 
dum, the non-transparent material of the corundum species. A 
few gems of the variety, sapphire, have been found at Hog Creek,, 
near Hiawassee, Towns county. These were small, prismatic 
crystals of ruby color, but somewhat cloudy. A few gems of 
sapphire are said to have been found at the Laurel Creek mine in 
Rabun county; this report, however, is not authentic. 

The corundum of Georgia is usually pink, gray or blue, these 
colors frequently occurring in the same specimen. Shades of red 
and light to dark-blue are common. White corundum is rare, and 
shades of yellow and brown have not been observed. 

Georgia corundum is not uncommonly found in crystals; gener- 
ally in six-sided prisms, and usually without terminations, though 
sometimes they are terminated by pyramidal faces. More highly 
modified forms have been found at the Laurel Creek mine. In the 
main, however, it occurs in small grains or blocks. Massive pieces, 
weighing several hundred pounds, have been taken from the Laurel 
Creek mine frequently, and much larger pieces are occasionally 
found. 

DESCRIPTION OF LOCALITIES. 

RABUN COUNTY. 

General Observations. — The corundum properties found in 
Rabun county, up to the present time, are located in the extreme 



DESCRIPTION OF LOCALITIES. 77 

eastern and north central parts of the county. Only one has been 
worked for corundum — the Laurel Creek mine; but this is famous 
throughout the country. Others have been worked for asbestus, 
and most all of them, on which corundum is known to occur, have 
received more or less attention. 

The county is extremely rugged, being broken up by steep hills 
and high mountains; but some of the innumerable valleys are un- 
surpassed by any agricultural lands in North Georgia, for richness 
of soil and productiveness. Moreover, access to any portion of this 
most northeastern county is comparatively easy. 

THE LAUREL CREEK MINE. 

Corundum was first discovered on Laurel Creek, in the early 
seventies by an Englishman, named Thompson. Colonel Jencks 
followed this discovery by examination, and worked intermittently 
during 1873 and 1874. Altogether, only a few month's work was 
put in, and the " find" seemed so poor, that the property was finally 
abandoned. In 1886, several men, living in the neighborhood, 
mined it for asbestus. Their mining was much hampered, by the 
frequent occurrence of hard and heavy rocks, which they were 
forced to remove. The nature of these rocks was unknown to 
them ; consequently they dumped them to one side. This damp 
was Corundum. Dr. H. S. Lucas of Chester, Mass., who, al- 
ready had been, for some time, actively engaged in corundum 
prospecting through North Carolina, hearing of these works, 
visited the locality, and at once purchased the property for the 
Hampden Emery Co. of Mass., which, for some years, practically 
controlled the corundum industry of the United States. 

Under the able management of Dr. Lucas, corundum veins were 
exposed, a plant was established, and what had formerly been a 
poor asbestus mine, soon became one of the main sources of supply 
to the corundum trade of this country. Work was continued from 
1880 to 1892 with eminent success. In the latter year, the hillside, 
under which they were working the most paying vein, caved in, 
and for a time work was paralyzed. At this time, they had 
reached a depth of 130 feet, and were working in a vein averaging 
.8 feet in width. Up to the summer of 1893, work was carried on 






7^ DESCRIPTION OF LOCALITIES. 

unsuccessfully at other points, the owners report, while a 
shaft was being run down through the debris to the main vein. In 
September of the same year, the mines were closed down, pending 
the financial stress. 

To this brief historical resume, a few words may be well added,, 
in regard to the advantages, which have accrued to the country,, 
from this single industry. Besides the heavy taxes, which have 
been paid on the property, by this company, and the natural increase 
in value of neighboring lands, a small settlement has been estab- 
lished, in the heart of a heretofore sparsely settled portion of the 
country; new roads have been built, old roads have been improved,, 
streams have been bridged, a saw-mill has been erected, and, by the 
generosity of the mine owners, three months have been added to the 
regular school term. 

Location and General Features of the Mine. — The 
Laurel Creek corundum mine, or " Lucas mine," as it is locally 
known, is situated in the southern portion of lot 72, 3rd district. 
Pine Mountain, the mining settlement, is about one mile southwest, 
and both are on the north side of Laurel creek, a small stream en- 
tering the west fork of the Chattooga river. It is for this creek,, 
that the mine is named. 

The sketch map l shows the position of the works, the relative 
position of the different formations, etc. From this, it may be 
seen, that the formation occupies two small hills. These stand out 
conspicuously to an observer, on account of their rough, barren na- 
ture and the rusty, ochre color of their rocky surface (so character- 
istic of chrysolite formations), offering, in external appearance, a 
sharp contrast to their environments. 

The original works are represented in the " sketch map," by 
the irregular-shaped cut at the right, marked B. From a tunnel 
at this point, the immense crystals pictured in Fig. 2 were taken. 
From the same vein, have been also taken those immense speci- 
mens of massive corundum, for which the mine is famous. The 
triangular cut at the left, near the shaft-house, marked A, works- 

1 See figure 6. 



DESCRIPTION OF LOCALITIES. 
Fig. 6. 



79 



Hornblende 

gnaijs 

Antnof>hyllite lyiyyi&l 



Chrysolite I^V-.V,. 1 ^ 




LEGENO 



E2Z3 



Sketch Majo 



t^H^ 



Scale of Ret 

• *2 

Contour Interval 20 Fcfct 



around the main vein, and is an excavation from the surface at the 
contact of the gneiss and the magnesian formation. This excava- 
tion extended around to the front of the hill, where the shaft-house 



80 DESCRIPTION OF LOCALITIES. 

now stands; but it does not show on this map, because of the cave- 
in, already mentioned. The work of 1893 was an inclined shaft, 
running down to the base of this old excavation, a depth of 130 
feet, and is located on the map by the shaft-house. 

The mill of the mine is situated a few hundred yards southwest of 
the shaft-house. This consists of a stamp-mill and other machinery 
for crushing and cleaning the vein material. Water is the motive 
power, and this is supplied by a small mill-race, extending from a 
dam near the mine, along the hillside south of the creek, to the 
mill. Corundum in its matrix is transported to this mill, by means 
of a tram-way, where it is cleanly separated and packed in bar- 
rels; it is then hauled to Walhalla, S. C, a distance of twenty 
miles, where it is shipped to the Chester factory, in Massachusetts. 

GEOLOGY OF LAUREL CREEK. 

Three types of rock are represented at Laurel Creek : — 

1. Gneiss. 

2. Hornblende-gneiss. 
Chrysolite, with a little chromite. 

" more or less serpentinized, _ 

3. Pendotite. 4 , . L , . . , . . y Dunyte. 
and associated with chromite. J 

Anthophyllite. 

The position of all these types at Laurel Creek may be seen in 
the Sketch Map, Fig. 6. 

Gneiss is the main inclosing body, and, as may be seen by the 
map, in the immediate vicinity of the magnesian body, its strike 
conforms to the shape of the inclosed mass. It consists of a schis- 
tose or stratified aggregate of feldspar, mica and quartz, differing 
from the mica-schist, in having a less foliated structure, and from 
granite, in the lamellar arrangement of its constituents. The strati- 
fication of the gneiss is accentuated by light and dark bands, some- 
times several feet in width, with, occasionally, a pegmatite vein or a 
coarse-grained aggregate of the same. 

At the contact of this gneiss with the intruded peridotite, we 
should expect a zone of metamorphosed material; but this is not 
visible. Evidently, therefore, this region has been much disturbed 



PLATE III. 




Corundum at Base of Chlorite Schists. 
Cut at Bell Creek Mine, Hiawassee, Towns County, Georgia. 



DESCRIPTION OF LOCALITIES. 8 1 

by earth movements, since the magnesian rocks became a part of 
its structure; and the original features have given place to later 
changes. 

Hornblende-gneiss lies on the eastern side of the peridotite for- 
mation. Outcroppings occur on the south side of Laurel Creek, and 
northeast of the shaft-house, where the tram-way cuts the base 
of the hill. At the latter point, we find the limit of an extension, 
or apophysis, from the main body lying to the east. The cut at the 
tram-way also shows the curving strata of the hornblende-gneiss, 
as it conforms to the elbowing gneiss. 

The peridotite body is seen to consist of two well divided areas. 
The northern hill consists mainly of chrysolite. Fresh material, 
taken from the cut at B, is composed essentially of massive chryso- 
lite, with a small percentage of magnetite and chromite. Hand 
specimens show a rock of granular structure, the grains varying 
from minute to a quarter of an inch in diameter. In color, the rock 
is mottled-green. On freshly fractured surfaces, the chrysolite 
grains present a very distinct cleavage and a vitreous lustre. 
Microscopic sections show that the chrysolite is somewhat altered, 
by the presence of small serpentinized cracks, chlorite and mag- 
netite. 

A chemical analysis of this rock, by Dr. William H. Emerson, 
gave the following results : — 

Chemical Analysis of Chrysolite. 

Si0 2 42.71 1 

MgO 41.18 

FeO . 6.83 

Al 2 O g 0.70 

NiO 0.32 

MnO 0.09 

CrO trace 

Ignition.. 8.38 

100.21 
Sp. Gr 3.10 

1 The silica contains a small amount of chromite, which was not determined. 



82 



DESCRIPTION OF LOCALITIES. 



The exterior portion of this chrysolite body consists of compact, 
fine-grained, olive-green rock, with phenocrysts of calcite and the 
calcium-magnesium amphibole, tremolite. Through these rocks, 
also, are visible dark streaks of magnetite, A microscopic exami- 
nation reveals, that the chrysolite veins are completely broken up 
by serpentinization and the development of magnetite and chromite. 

The anthophyllite, which occupies the southern portion of the 
peridotite formation, and tongues north through the chrysolite, is 
supposed to be an alteration product of the chrysolite. It will be 
seen by the map, that this makes up about one-third of the entire pe- 
ridotite body. 

The rock consists essentially of fibrous anthophyllite, magnetite 
and scales of a bright green chlorite, with talc occurring in it, oc- 
casionally. Its color is brownish green. The specific gravity is 
noticeably heavy. On account of its fibrous character, it is fre- 
quently spoken of as " asbestus rock." 

It is much to be regretted that, at the time of survey, the condi- 
tion of the mine was such, that access to tunnels etc., was impossible. 

Dr. Chatard, however, who spent some time at this mine prepar- 
atory to writing his bulletin on " The Gneiss-Dunyte Contact of 
Corundum Hill, N. C, in Relation to the Origin of Corundum," 
writes : — "The two localities are alike in respect to the occurrence of 
the corundum. In both, the mineral is found in chlorite and ver- 
miculite, lying between hornblende-gneiss and altered dunyte. At 
Laurel Creek, the open cut, in which the corundum is mined, runs 
east io°, 20° north, following the course of the veins, the mine be- 
ing situated on the north bank of Laurel Creek, at the base of a high 
hill. On the south bank and in the bed of the creek, hornblende-gneiss 
is the country rock, succeeded as we go northwardly by enstatite, 
talc and allied minerals. The corundum, first met with, occurs in 
what is locally known as the " sand vein," which is composed of 
chlorite and vermiculite carrying more or less corundum, usually in 
small crystals and fragments. The chlorite in the upper portion of 
this vein was much disintegrated ; the mass, falling readily to pieces, 
allows of the easy removal of the corundum; but, at the time of my 
visit, it was very compact and tough, and of little value. The sand 



DESCRIPTION OF LOCALITIES. 83 

vein is succeeded by a so-called " horse " of steatite, on the other 
side of which is the vein of "block corundum." This is a vein of 
vermiculite containing masses of corundum, sparingly mixed with 
chlorite and vermiculite, and frequently of great size, several having 
been obtained, of at least 55°o° pounds in weight. One mass, which 
I saw, must have weighed at least a ton. The north wall of the 
block vein is a smooth wall of " indurated talc " and steatite, which 
gradually passes into altered, but still hard, dunyte. Indeed, the 
difference between this place and Corundum Hill is in no respect 
more marked, than in the greater hardness and toughness of the co- 
rundum-bearing rocks, and in the apparent concentration of the co- 
rundum into large masses, with but little evidence of crystallization* 
At the western end of the cut is a vein of decomposed white mate- 
rial, shown by analysis to be an altered soda-lime feldspar. In this, 
I did not find any corundum; but I was told, that it was occasionally 
found in this rock." 

This description of those features, which he desires to bring out, 
would tend to confuse an observer. It will be seen by the map, that 
the hornblende-gneiss does not come in direct contact with the 
dunyte; but there is an intervening formation of gneiss. Moreover, 
the mineral, corundum, is not confined to vermiculite and chlorite, 
if the report of the miners is to be credited; but it is abundant in 
the lime-soda feldspar. The testimony was corroborated by the 
presence at the mill of several tons of feldspar, thickly studded 
with corundum. 

THE HICKS ASBESTUS MINE. 

Lot 81, 3rd District. 

In the range of lots north, and cornering the land lot of the 
Laurel Creek mine on the east, is a formation, similar in character, 
known as the Hicks Asbestus mine. The formation, however, is 
much smaller apparently, a little over half as large. Corundum is 
reported to have been found here in small quantities; but the dis- 
coverers are said to have " salted " the property, with specimens 
from the Laurel Creek mine. 

Considerable asbestus was taken away, and shipped, eight or ten 
years ago; and since then the property has been abandoned. 



84 DESCRIPTION OF LOCALITIES. 

It is supposed to be a continuation of the Laurel Creek forma- 
tion; but this cannot be proven by the outcroppings. It is true, 
that the same gneissic hornblende dyke passes on one side of these 
two properties; further than that, there is no connection. 

LOTS 27 AND 28, 3RD DISTRICT. 

This property belongs to the Nicholson heirs, living in the vicin- 
ity of Pine Mountain. It was worked for asbestus about the same 
time as the Hicks property. 

The outcroppings are in the form of large bowlders of a talcose 
anthophyllite, similar to that found at the Laurel Creek mine; but 
outcroppings of like character may be found at intervening points, 
from Laurel Creek, alongside the same gneissic hornblende dyke. 

This property is mentioned, because corundum is reported to oc- 
cur here. 

beavett's mine. 
Lot 177, 2nd District. 

This property belongs to Capt. Beavett of Rabun Gap. The 
formation covers a little over an acre, and is made up of soapstone 
and anthophyllite. The development, which consists only of a 
" test-pit," is on the top of a little spur. Basic magnesian rock 
makes up the entire formation of this little spur, while on either 
side is gneiss. On the northeast side of the hill, hornblende-gneiss 
sweeps down, striking 35 ° west of south, and, with the gneiss, dips 
to the southeast. 

At the bottom of the pit, under a large bowlder, several pounds 
•of corundum were found in vermiculites. The largest crystals 
taken from this vein are not over one-third of an inch long and a 
quarter of an inch in diameter. All are prismatic, and thoroughly 
impregnated by scales of vermiculite. After this discovery, work 
was abandoned. On the same lot and the adjoining north lot, a 
larger and more favorable formation occurs. 

LOTS 177 AND l88, 2ND DISTRICT. 

The magnesian rocks on this property extend over about two 
acres, and are made up of chrysolite and anthophyllite. The strike 
of the formation is about 45 ° west of south. Its greatest width is 



DESCRIPTION OF LOCALITIES. 85, 

at the northeast, where it is about one hundred and fifty yards 
wide, measured at right angles to the strike. The formation main- 
tains this width, as well as can be determined, for over two thou- 
sand feet, when it pinches out. 

The country rock is gneiss. Hornblende-gneiss is also present,, 
as with other formations of similar character in Rabun county. 
Both types of rock dip sharply to the southeast, and strike south- 
west. 

Very little work has been done on this property; and, up to the 
time of survey in the Fall of 1893, no corundum had been found. 
At this time, Mr. J. A. Lamb and his crippled son, who live close 
by, were digging a few holes; but, having comparatively little 
knowledge of prospecting for corundum, their toil was fruitless. 
Following, however, the lines of rock pointed out to them by the 
writer, a few days' work opened up a vein eighteen inches wide, in 
which small granular and crystal corundum was quite abundant.. 
The vein was of the first type, that is, a gangue of kaolinized feld- 
spar, quartz and phlogopite. Two inch walls of chlorite inclosed 
the vein on either side. The corundum was found in " pockets," 
lying close to the west wall. No corundum was found 
in the chlorite wall. This vein is situated in the extreme north- 
eastern part of the magnesian formation, and within a few 
feet of the contact with the gneiss. It increased in width, as the 
workmen enlarged the pit, and offered good prospects for a forma- 
tion of this size. Only a few pounds of corundum were washed 
out, and then the work was left for the inspection of possible 
buyers. 

The corundum taken from the vein is grayish-white, grayish- 
blue and dark-gray. It was without crystal form usually, and not 
encased by any mineral ; hence it was easily cleaned from the vein 
matrix. The specimens in the possession of the Survey are minute 
crystals, of prismatic and pyramidal type, and irregular grains, all 
showing the characteristic lines of pseudo-cleavage. 



86 DESCRIPTION OF LOCALITIES. 

LOT 157, 2ND DISTRICT. 

In the lot on the north side of the ridge at Lucius Garland's 
house, is a large outcropping of peridotite, known to the neighbor- 
ing people as " Soapstone Mountain." Its length on a north and 
south line is about 300 feet, its width 100 feet. 

The outcropping consists mainly of talcose anthophyllite. Its 
country rock is gneiss and hornblende-gneiss. 

This property is mentioned, because of its size and the fact, that 
no prospectors seemed to have worked upon it. This neglect by 
prospectors is due, in all probability, to the ignorance of its char- 
acter, on the part of those acquainted with its existence, and to its 
inaccessibility. No corundum had been found here, at the time of 
our visit; but the property is worthy of investigation. 

LOT 7, 1ST DISTRICT. 

No corundum has been found in this district, and of the proper- 
ties examined, only one seems worthy of special mention — lot 7. 
This property is said to belong to Dr. H. V. M. Miller of Atlanta. 
It was worked, several years ago, by Mr. Ashbury, for asbestus. 
Considerable asbestus is said to have been mined, before the work 
was abandoned. 

This peridotite formation is about five hundred and fifty yards 
long and two hundred yards wide. It is made up, as far as can be 
determined, by outcroppings, entirely of chrysolite, changing into 
chromiferous chrysolite at the northeast. It differs, therefore, 
from other peridotite formations in Rabun county, by the absence 
of anthophyllite. The country rock is gneiss, while hornblende- 
gneiss lies close by, on the northwest side. 

All the mining for asbestus was in the nature of deep open 
trenches, confined to the southwestern, and central portion of the 
formation, but some distance from the contact with the gneiss. No 
corundum veins were cut by these; and, in the light of present 
knowledge, this result is not surprising. Until, therefore, pros- 
pecting has been carried on, near the contact with the gneiss, this 
property should not fail, for lack of a little development. 



DESCRIPTION OF LOCALITIES. 87 

TOWNS COUNTY. 

The known corundum deposits of this county are confined to the 
western side of the 18th district, and the eastern and central por- 
tions of the 17th district. Those of the 18th and the eastern portion 
of the 17th lie within a few miles of Hiawassee, the county-seat, 
while the remainder are in Brasstown Creek valley and vicinity. 

THE BELL CREEK MINE. 

Lot 6, 18th District. 

This is one of the richest and most interesting little proper- 
ties in the State. It is located about four miles north of Hia- 
wassee. Its extent, concealed by surface disintegration, explora- 
tion has not determined, since testing has been confined entirely 
to the outcropping, which is not more than one hundred feet 
in diameter. A short time previous to the survey, the walls of 
the main pit had been blasted in, by an irascible prospector, for 
fancied injuries at the hands of the owner. He did not disturb the 
dump, however, which is full of granular corundum up to the size 
of a half inch in diameter. In his mining, such small pieces were 
evidently considered unworthy of notice. From this, the nature 
of the veins was determined. 

The outcropping is made up of chrysolite, anthophyllite and chlo- 
rite-schist. Gneiss and hornblende-gneiss form the country rock, as 
shown by the soil and by small outcroppings of the former, on the east- 
ern side. The main pit, already mentioned, was about twelve feet 
in all dimensions, and was sunk through chlorite-schists. These are 
stratified, and dip about 45 to the southeast. The vein follows the 
stratification of the chlorite. Plate III shows one of the walls of 
this pit, with a small exposure of the vein, in the lower left hand 
corner. The gangue of this vein is kaolinized feldspar. This is 
rich in beautiful pink corundum. In the dump, pink corundum was 
found in the wall material (compact, scaly, dark-green chlorite); 
but, at this small exposure, it does not show, in the three-inch wall. 

The dump of another pit (the pit itself was full of water) re- 
vealed the presence of the fourth type of vein — a massive aggregate 
of pink corundum and light green smaragdite with feldspar. As a 



88 



DESCRIPTION OF LOCALITIES. 



cabinet specimen, there are few rocks prettier than this. The owner 
of this property, Mr. Wm. R. McConnell, was not able to give any 
information, in regard to the character of its occurrence, which is 
unfortunate, since this is the only specimen of the class found in 
Georgia. Moreover, its presence seems to be confined to only a few 
localities in this country. The specimens, obtained for the Survey,, 
differ slightly from material in our possession, from Buck Creek, 
North Carolina; the amphibole is a little lighter green, while the 
corundum does not attain the deep ruby color of the Buck Creek 
variety. 

THE HOG CREEK MINE. 

Lot 92, 17 'th District, 

The Hog Creek mine is situated on the northwestern portion of 
lot 92, about two miles west, a little south, of Hiawassee. More work 
has been done on this property, than at the Bell Creek mine, because 
of its greater extent and prospects. A trench, east and west, ex- 
poses the character of the formation, and several pits have been dug 
in close neighborhood, in the search for veins. Despite these, there 
has been little development; and, although the prospects are bright,. 
an approximation of its value will necessitate further development. 

Pink corundum prevails here, as at Bell Creek; but the veins in 
sight are not so rich. It is from this mine, that the Georgia rubies 
were taken. The writer was informed by the owner, Mr. William 
R. McConnell, that those found by him were small prismatic crys- 
tals of good color, but cloudy. Blue and grayish-white corundum 
is also found here. 

The vein now exposed is about four feet wide. It is of the first 
type, that is, a matrix of feldspar, quartz and phlogopite, and lies 
in chlorite-schist. Both the vein material and the chlorite-schist are 
much decomposed through superficial disintegration. Plate IV 
shows the vein with the inclosing chlorite-schist. The strike is 
about 30 east of north; and its dip is 70 southeast. The cut fol- 
lows this vein about twenty feet, and goes down on it eight feet. 
Corundum is present, not only in the feldspar gangue, but also in the 
chlorite walls; when in the latter, it has a pink color. 



DESCRIPTION OF LOCALITIES. »9 

Besides chlorite-schist, the formation is made up of chrysolite 
and anthophyllite ; these latter show in the form of surface bowlders. 
Gneiss and hornblende-gneiss surround the formation. 

From a mineralogical standpoint, this locality is interesting, in be- 
ing the only corundum locality known in Georgia, where the mineral 
zoisite occurs. The specimen now in the possession of the Survey 
represents a portion of what was, before it was broken by the work- 
men, a surface bowlder of zoisite, encased in finely fibrous actinolite, 
over a foot in diameter. Sheets of the latter also spread through it, 
forming abase for the slightly radial, columnar arrangement of the 
needles of zoisite. Actinolite, in the form of minute light-green 
needles is, besides, occasionally found interlined with the needles of 
zoisite. Dr. Genth x has described zoisite as an alteration product 
of corundum; but no corundum is present on this specimen. In the 
future developments of this property, zoisite will probably be found 
in situ, and its relation to corundum may here be revealed. 

On account of its rarity and the fineness of the specimen, an 
analysis 2 was made, with the following results: — 

Si0 2 38.29 

A1 2 O s 33.38 

Fe 2 O a i.Si 

CaO . 24.19 

MgO 0.93 

Ignition _.. 1.80 

Alkalies Undetermined. 

Total 100.10 

Sp. Gr 3.35 

Occurring on this lot, also, and as probably a continuation of the 
formation, is an outcropping of chromite, in which a chrome-ore 
vein has been opened. Genthite 3 is also present, as an incrustation 
on chromite. Some large blocks of feldspar, thickly studded with 
corundum crystals, were found in this cut, apparently in situ. 

1 See zoisite, page 46. 

2 Analysis by Dr. "William H. Emerson. 

3 See page 56. 

7 



9° DESCRIPTION OF LOCALITIES. 

LOT 42, 2 3RD DISTRICT. 

This lot belongs to Mr. J. N. Gibson of Hiawassee. Two dis- 
tinct magnesian formations extend through it; and, on both, corun- 
dum has been found. In the fields southeast of' his home, in the 
southwestern corner of this lot, a shaft ten feet square was sunk, 
several years ago. Corundum was found; but, the find not prov- 
ing satisfactory, work was abandoned. Surface disintegration is 
quite deep here, and the only clue to the occurrence of corundum 
was its presence on the surface. In the northwest corner of the 
same lot, on a formation distinct from that of the southwest corner, 
a type of vein, different from any previously described, was ex- 
posed by Mr. Gibson. This vein is of the third type, and is mas- 
sive-porphyritic in character. It is made up of large 1 hypidio- 
morphic crystals 2 of a black hornblende, with lime-soda feldspar, 
and irregular grains of grayish-white and blue corundum, frequently 
an inch or more in diameter. The hanging and foot walls are 
massive hornblende. Bowlders of this appear on the surface; but no 
outcroppings occur. 

If this vein, which is about four feet wide, continues as uniformly 
rich in corundum, as present work forecasts, its economic value 
does not seem doubtful. Increase in the expense of working, 
as compared with that of the usual veins, will probably be 
compensated for, by the greater abundance of corundum. 

OTHER CORUNDUM PROPERTIES NEAR HIAWASSEE. 

Here are included lots, on which surface-corundum has been 
found; but no prospecting nor any attempt at development has been 
made. Outcroppings, if present, are small; and surface disinte- 
gration and "wash" have completely concealed the real extent of 
the formations. Following are the lots: — 

Lots 4, 5, 34, 35, 36, 41, 43, 73, 17th district, and lots 89, 90, 91, 
1 8th district. 



1 These crystals are often several inches in length and an inch or more in width. 
2 That is, crystals only partially bounded by crystal planes. 



DESCRIPTION OF LOCALITIES. 9 1 

THE HAMILTON MINE. 

Lot 6o, 17^/1 District. 

The Hamilton mine is noted mainly for the lawsuit, in which it 
has been involved for several years past, and the large sum of 
money spent by Mr. Hamilton in its fruitless development, as 
brought out in court. It is located about five miles north of Young 
Harris, on a western spur of a range of hills forming the western 
boundary of Brasstown Creek valley, trending north and south, 
and culminating, at the south, in the highest peak in Georgia, Mt. 
Enota. 

The works are located on the top of this spur, and consist of 
several prospecting pits, and a perpendicular shaft about 100 feet 
deep. 

The formation is similar to that at Track Rock, though smaller. 
Its greatest width is in the saddle of the spur, pinching out rapidly, 
as it descends the spur on either side. The rocks brought out 
from the shaft are of the same type as those described at the 
Track Rock mine. * 

The corundum, as at Track Rock, occurs encased in margarite. 
Sometimes the margarite scales lie flat upon the corundum, while 
other specimens show a zonal arrangement, with upturned edges, 
the latter type being more apparently an alteration of the corun- 
dum. Specimens of the actinolite-margarite rock were here found, 
containing corundum; otherwise the vein matrix for corundum was 
the same as at Track Rock. A section of the material penetrated 
by the shaft could not be obtained. 

BRASSTOWN CREEK VALLEY CORUNDUM PROPERTIES. 

These properties represent an almost direct southwest line of 
basic magnesian formations, extending through the Hamilton prop- 
erty, and connecting with the formations leading on to Track Rock, 
Union county. They occur on lots 23, 50, 60, 84, 85, 97, 118, 119, 
135, 171, 190, 17th district. 

1 See pages 93 and 94. 



9 2 DESCRIPTION OF LOCALITIES. 

UNION COUNTY. 
Only a few deposits of corundum have been found in Union 
county, and these lie in the northwestern portion of the county. 
In this county, however, the almost continuous line of deposits of 
Brasstown Creek valley, Towns county, culminate in possibly the 
second largest peridotite formation in Georgia, the Laurel Creek 
mine ranking first. In this deposit is the Track Rock mine. 

TRACK ROCK MINE. 

Lot 259, i*jth District. 

Track Rock mine is located on the south side of Track Rock 
gap in the northeastern portion of Union county. The mine has 
been developed only partially ; but already it shows excellent pros- 
pects. A large mill is conveniently located near the entrance to 
the tunnel. Water for washing the vein matrix is brought by an 
acqueduct from a little stream close by. The machinery, by means 
of which the company separates the corundum, is run by steam. 

The present development is a tunnel to the right of the mill, 1 
which enters the magnesian formation from its eastern side. 

The company has penetrated the formation about two hundred 
feet, branching out at several points. Although the tunnel is 
slightly inclined, to permit good drainage, they have, by this means, 
reached a depth of seventy-five feet from the surface level at the 
extreme end of the tunnel. 

The formation differs considerably from the class of formations, 
represented by the Laurel Creek region. From a superficial in- 
spection of this property, one would conclude, that the formation is 
made up of talcose -chlorite schists to the complete exclusion of 
chrysolites. Instead of a barren area of anthophyllites and serpen- 
tinized chrysolite, as at Laurel Creek, we are here confronted by a 
heavily wooded area, over whose rich soil are scattered large 
bowlders of a talcose chlorite or " blue soapstone," as it is locally 
termed. 

The presence of corundum on such a formation tended to con- 
fuse preconceived ideas of the nature of corundum-bearing forma- 
1 See Plate V. 



DESCRIPTION' OF LOCALITIES. 93 

tions in the North Carolina-Georgia region. Corundum prospec- 
tors, moreover, have come to speak of the Track Rock mine as a 
" chlorite mine," in contradistinction to a " chrysolite mine.'' The 
Survey, however, found that these chlorites were simply a secondary 
feature, since most of the material taken from the tunnel, which 
had been passing muster for chlorite, was really a bright green am- 
phibole, actinolite. Among the rocks taken from the mine, is a 
dark-green, finely granular rock, which was supposed to be massive 
chlorke. 

This latter rock is most interesting, because it affords a key to 
the mystery of the formation. Instead of being massive chlorite, 
it is an altered chrysolite, consisting of fine blades of actinolite, small 
granules of chrysolite, and an abundance of magnetite. A thin sec- 
tion, examined under the microscope, shows that the chrvsolite has 
undergone extensive change. Cracks in the remaining ch^solite 
grains are widely extended, and are filled in by actinolite (?), while 
small grains are completely isolated by enclosing actinolite. The 
large percentage of magnetite is also probably due to the alteration 
of chrysolite. 

On account of the close timbering of the tunnel, it was impossi- 
ble, at the time of survey, to see the sequence of formations pene- 
trated, but the foreman, Captain R. J. Cook, who is now living on 
the property, had kept a record of these, from which, together with 
the dump and material obtainable in the tunnel, the following sec- 
tion was determined, viz: — 

i. Thirty feet of micaceous gneiss. 

2. Ten feet of talcose-chlorite schist. 

3. Thirty feet of soft, greenish material and pearly white scales; 

the former, actinolite, the latter, margarite. 

4. Four feet of hard, massive, dark-green rock, with gneissic 

structure, made up of actinolite and a lime-soda feldspar 
(oligoclase (?)). In this are bands of compact, scaly green 
chlorite. 

5 . Twelve feet of extremelv disintegrated light-green material, 

consisting mainly of kaolinized feldspar, with a smaller pro- 
portion of light-green actinolite. Corundum is present in 
this. 



94 DESCRIPTION OF LOCALITIES. 

6. Four feet of the same material as 4. 

7. Twenty-four feet of material similar to 5. This is rich in 

corundum. 

8. Four feet of material like 4 and 6. 

9. Ten feet of material similar to 5 and 7? but not so rich in 

corundum. 

10. Forty feet of lime-soda feldspar, in which hard bunches of 

feldspar remain unkaolinized. Mica (phlogopite) is scat- 
tered through this, but no trace of quartz. 

11. Ten feet of talcose-chlorite schist. 

12. Twenty feet of the soft, decomposed material like 5, 7 

and 9, with some corundum. 

The altered chrysolite, described on page 93, does not appear in 
this series; and, unfortunately, its position could not be learned. 

Although, this section is doubtless wanting in considerable de- 
tail ; nevertheless, from this series, such as it is, a few interesting 
and important facts maybe observed: — (a) the new phase of alter- 
ation in the chrysolite ; (b) the absence of anthophyllite rocks ; 
(c) the presence, in close vicinity to each other, of broad parallel 
corundum veins; (d) the character of these veins; and finally, of 
marked significance, (e) the presence of these veins near the gneiss 
contact. 

All the material, mentioned in the above section of Track Rock 
mine, may be duplicated at the Hamilton mine, and will probably 
be found, on the development of any of the corundum properties, 
extending through Brasstown Creek valley. The chrysolite of the 
Hamilton mine is of a lighter shade of green, than the one described 
here; but this is probably due to its less altered condition and its 
smaller percentage of magnetite. 

The formation at Track Rock mine strikes southwest 30 , and 
dips to the southeast about 40 . The corundum veins lie in the 
stratification of this formation, and conform to its structure. None 
of these veins have been followed any distance; but, during the 
brief period of work, preceding the financial troubles of the sum- 
mer of 1893, when work was stopped, several tons of corundum 



DESCRIPTION OF LOCALITIES. 95 

were cleaned and shipped to the mills of the owners, "The New 
York Corundum and Mining Company." 

The corundum obtained from the veins is in small irregular 
pieces, encased in a mantle of pearly, grayish-white margarite. 1 
The process of cleaning and preparing this corundum for shipment 
will be described in the chapter on "Economics." 

OTHER CORUNDUM PROPERTIES IN UNION COUNTY. 

Lots 208, 244, 282, 295, 318, i*] th District. 

All these lots have been indifferently prospected for corundum. 
The amount found, however, and the lack of interest on the part of 
speculators has not enthused the owners to put any time or money 
into their development. Outcroppings of the basic magnesian 
rocks are small, if present; and deep surface disintegration charac- 
terizes the majority. 

THE STONE MINE. 

Lot 246, i*ith District. 

This property lies in the southeast corner of lot 246 on the north 
side of Track Rock gap, and on the east side of the road. It is a 
part of the Track Rock formation, and presents no differences, ex- 
cept in size. A twenty-foot tunnel, running from the road into the 
hillside, passes through talcose-chlorite schist into brownish-yellow 
banded, but completely disintegrated, material, through which, par- 
allel with the band, are stripes of feldspar containing corundum. 

The development is too slight to offer any assurance of its value. 
The formation, however, is large enough to induce further pros- 
pecting, and some good veins may be developed. This property 
belongs to Mr. J. H. Stevens, and it was under option to northern 
parties, represented by Mr. Robinson of Young Harris. 

FANNIN COUNTY. 

Corundum has been reported from this county; but no occurrence 
is yet known to the Geological Survey. 

1 This was determined by Dr. Emerson, from a partial analysis. 



96 DESCRIPTION OF LOCALITIES. 

GILMER, PICKENS AND DAWSON COUNTIES. 

Corundum is not known to occur in any of these counties; but it 
is quite possible that it may be found in Dawson. 

LUMPKIN COUNTY. 

Corundum was first found in Lumpkin county, in the summer of 
1894. Only one locality is known. 

Lot 249, i$th District, 1st Section. 

About one mile southeast of the summer resort, Porter Springs, 
on the eastern side of lot 249, a low outcropping, seventy feet wide 
and two hundred feet long, was discovered by a child to contain co- 
rundum. This property belongs to Charles Cain, whose home is 
but a few yards from the outcropping. A prospector had given Mr. 
Cain's little boy a piece of corundum, with the injunction, " Dig for 
it in those green rocks, and make your fortune." The little chap 
went to work bravely, and his scratching was rewarded by a few 
pounds of grayish-white, blue and pink blocks of corundum. 

The formation consists of massive hornblende. No work has 
been done to develop the property, and its size and prospects will 
probably not warrant the expense. 

WHITE COUNTY. 
Corundum has not been found in White county; but the corun- 
dum deposits of Habersham county are close to the northwest bound- 
ary ; and, furthermore, basic magnesian formations continue on into 
White county from this vicinity, and are known to occur at several 
other points in that county. Careful prospecting will undoubtedly 
reveal in some of these the presence of corundum. 

HABERSHAM COUNTY. 
The first authentic knowledge of the occurrence of corundum in 
Georgia seems to have been the mention of a specimen from Haber- 
sham county. It is only in the past year, however, that an active search 
has been made for corundum in this county; but, in that brief time, its 
distribution is, perhaps, as well known, as that of any other section of 
the State. This is due almost entirely to the tireless energy of a few 
men, prominent among whom may be mentioned Mr. Thomas S. 



DESCRIPTION OF LOCALITIES. 97 

Bean of Clarksville, and Messrs. A. J. Lyons and William Trotter 
of Soque. The information of the latter is confined to the north- 
western portion of Habersham county, while Mr. Bean is well versed 
in the mineral resources of the whole county. 

The known corundum properties of Habersham may be said to 
lie in the Aleck mountains, a small range in the northwestern part, 
of the county. Despite, however, the number of occurrences in 
this section, there is not a property, which has been developed, and 
only a few, on which any work has been done. This is accounted 
for, not by reason of a lack of interest or faith on the part of those 
controlling the property, but on account of the unfortunate coinci- 
dence, that, at the time of discovery, capital was panic-stricken, and 
the corundum industry, in both North Carolina and Georgia, was 
at a stand-still. Nevertheless, when this industry is resumed, there 
is no doubt, but that some of these properties will receive careful 
attention. 

PROPERTIES ON WHICH CORUNDUM HAS BEEN FOUND. 

Lot 1 1 8, nth District. 
This lot is owned by Mr. E. P. West of Clarksville. Mr. E. T. 
Whatley, formerly Assistant State Geologist, had a small ditch dug 
across the small outcropping of peridotite in this lot, and he is re- 
ported to have found several pieces of corundum. 

Owner. 

E. Kimsey. 

F. E. Asbury. 

John Elder and John Tatum. 
John Elder. 
a. B. Elder. 

{ Wm. Trotter, 
| James Stroud, 
133 " -j F. E. McCracken, 

I Tillman Worley and 
\^E. Kimsey. 

In the lots enumerated above, some surface-corundum has been 
picked up; but no work has been done, except in the last. The for- 
mation extending through them, the outcroppings show to be chlo- 



Lot. 


District, 


125 


nth 


126 


a 


127 


a 


131 


u 


132 


a 



98 DESCRIPTION OF LOCALITIES. 

ritic; and it is probably similar in character to those of Brasstown 
Creek valley, Towns county, and Track Rock, Union county. Sur- 
face relations show this to be one hundred yards in width at several 
points. On lot 133, a trench 5 x 10 x 5 feet has been dug on the slope 
near the top of a small hill; and fifty pounds or more of beautiful 
corundum enclosed by margarite l has been taken out. The gangue 
of this corundum is reddish dirt, like the country material; and, on 
account of this superficial decay, it is impossible to tell anything 
about the character of the body, through which it is disseminated. 

These specimens of corundum have attracted considerable atten- 
tion, on account of their beauty. When taken from the pit, they re- 
semble externally lumps of white clay; broken open, however, a 
nucleus of beautiful red corundum, with a zonal mantle of delicate 
pale-green margarite is revealed. 

Lot 134 is interesting, on account of the presence here of a vein of 
the third type, consisting of black hornblende, lime-soda feldspar 
and corundum, as shown by surface specimens. 

LOT l6, 3RD DISTRICT, LOT 129, IITH DISTRICT, AND LOT 17, l6TH 

DISTRICT. 

Through these lots, belonging to Mr. A. J. Lyons, a small mag- 
nesian formation extends, and several pieces of block corundum 
have been found while ploughing. 

Information, in regard to any of these occurrences in Habersham 
may be obtained from Mr. Lyons or Mr. Bean. 

HALL COUNTY. 
Corundum is known in Hall county only at one locality. 
Beautiful red pieces of corundum have been found, for many years, 
by gold washers, in a small stream one mile west of Gainesville. 
Its source seems to have been recognized by a few; but it cannot 
be learned, that any specimens have been found, except in the sands 
of the stream. The locality has been well known to mineralogists 
for some time, not only on account of the beauty of the corundum, 
but because of the delicate green margarite found associated with 
it, an analysis of which, published by the chemist of the United 
States Geological Survey, is given on page 99. 

1 Determined by Dr. Emerson, from partial analysis. 



DESCRIPTION OF LOCALITIES. 99 

The Survey examined this property in the summer of 1894, and 
found that the stream flowed by the eastern base of a small hill; 
that the backbone of this hill consisted of magnesian rocks; and 
that, at the northern end of the formation, in the ploughed field, 
north of the old road leading over the hill, corundum, associated 
with margarite, was abundant. Previous to this time, the presence 
of corundum on the hill had escaped the notice of its owners, be- 
cause of the margarite mantle. There, the dull, dirty, nodular 
bowlders in the field — some of them as large as a man's head — 
failed to attract the attention of those looking for the bright, glis- 
tening, red corundum of the stream-sands below, when a blow of 
the hammer would have revealed the object of their search. 

The specimens of this material, now in the collection of the Sur- 
vey > range from one to six inches in diameter. Through these are 
scattered grains of corundum from a quarter to one and a half 
inches in diameter. Around these grains the margarite is zonally 
arranged; and, if not an alteration of the corundum within, it cer- 
tainly resembles it. 

The margarite in these specimens is grayish-white to a delicate 
pale-green in color. The zones are made up of small, pearly, radi- 
ating scales, with their edges tangential to the corundum nucleus* 
An analysis 1 of this mineral shows : — 

Si0 2 32.15 

A1 2 3 49.28 

Fe 2 O s _ 0.57 

CaO 1 1 .09 

MgO 0.63 

Na 2 1. 18 

K 2 1.04 

H 2 4.16 

100.10 

Sp. Gr 3.004 

1 Analysis made by Dr. T. M. Chatard, and quoted by Clarke, Am. Jour. Sci., 3rd 
series, Vol. XXVIII., 1884, p. 22. 



IOO DESCRIPTION OF LOCALITIES. 

The formation consists of pale greenish-white chlorite-schists 
and anthophyllite; large bowlders of the latter occur on the south 
side of the old hill road. 

An analysis of the chlorite-schist was made by Dr. George A. 
Koenig, because, on account of its color, it was thought to be a talc- 
slate. He found it to be a true chlorite-schist, containing : — 

Si0 2 _... 30.33 

A1 2 3 ._. .. 20.90 

Fe 2 O s 4.00 

FeO__ : 4.11 

MgO 27.79 

Ignition 1 2.62 

99-75 

The strike of the chlorite-schist is 25 west of north; the dip is 
45 to the southwest. This is a rare instance of the deviation of 
these structural features from the normal structure of the Crystal- 
line Belt. Several deep pits have been sunk on the south side of 
the road, in an attempt to find good asbestus veins. This seems to 
have been a failure, the asbestus veins exposed being small, and the 
quality inferior. 

The formation is about a quarter of a mile long and 100 feet 
wide. Though small, the abundance of corundum, that has been 
found here, should induce testing. Its close proximity to Gaines- 
ville, with her supplies and railroad conveniences, would probably 
sustain the development, even if the output was small, when a much 
larger mine would fail, for lack of: such facilities. 

This property is controlled by Major Theodore Moreno of 
Gainesville. 

FORSYTH COUNTY. 

The occurrence of corundum in Forsyth county was first noticed 
a year ago. Its presence here, except in one instance, is peculiar, 
in so far as the only known trace of its existence is its presence. 

LOT 1,274, 2ND DISTRICT. 

This lot is about one mile north of Sheltonville, and belongs to 



DISTRIBUTION OF CORUNDUM IN GEORGIA. IOI 

Mr. Tuggle, Jr. Corundum has been found in his yard, both by 
himself and by neighbors, although mica-schist and garnetiferous 
hornblende-gneiss are the only types of rocks in the vicinity. 

LOT 447, 1ST DISTRICT. 

Corundum is reported to have been found on this lot; but its pres- 
ence is very questionable. 

LOT 776, 2ND DISTRICT. 

Several little blocks of corundum were found by the writer on 
this lot, close by some small anthophyllite bowlders. Beyond the 
presence of these bowlders, all evidence of a basic magnesian 
formation is concealed. The occurrence is evidently of no eco- 
nomic importance. 

CHEROKEE COUNTY. 

A corundum deposit is reported east of Ball Ground; but we 
were not able to locate the property. It is quite probable, that 
some deposit will be found in the eastern part of this county. On 
Mr. S. J. BlackwelPs property, lots 36, 37 and 108, 2nd district, 
2nd section, there is an extensive formation of Pyroxenite (?), in 
which some large veins of asbestus have been exposed. Outcrop- 
pings of a similar character, but smaller, extend north several miles. 
No corundum has yet been observed. 

COBB COUNTY. 

In this county, corundum has been found only in the southwestern 
corner. 

LOT I236, 2ND SECTION, I9TH DISTRICT. 

Mr. Elias Rogers, of Villa Rica, prospected considerably on this 
lot a few years ago, but without success. A little corundum is 
found scattered over the surface. 

The property is owned by Mr. W. B. Westmoreland of Aus- 
tell, Ga. 



102 DISTRIBUTION OF CORUNDUM IN GEORGIA. 

CORUNDUM IN THE VICINITY OF POWDER SPRINGS. 

Surface corundum has been picked up in the vicinity of Powder 
Springs, on a " lead " extending from lot 684, which belongs to Mr. 
Henry Reeves, to Brownsville, Paulding County. 

Outcroppings of basic magnesian rock are very rare, surface dis- 
integration and wash, generally, concealing the formation. Only 
one point has been worked for corundum, a description of which is 
as follows: — 

LOT 1 27 1, 2ND SECTION, IQTH DISTRICT. 

On the farm of Mr. W. B. Turner, about two miles south of 
Powder Springs, corundum occurs in workable quantities. At the 
time of the New Orleans Exposition, large surface specimens from 
this farm, which had been sent for exhibition, attracted the atten- 
tion of a German syndicate, who, shortly afterwards, purchased the 
mineral interests of the property. Several months were spent in 
prospecting ; and when a vein was finally exposed, work ceased. 

This vein, between five and six feet in width, is of the first type. 
It lies between chlorite-schists, striking and dipping with the coun- 
try rock. The strike is 50 east of north, and the dip 45 south- 
east. The vein is exceedingly rich in corundum, which is dissemi- 
nated through it, in streaks, parallel to the dip of the vein, rather 
than in " pockets," and more thoroughly, than in any vein of this 
type, which has been exposed in the State. 

The corundum of this vein occurs in small irregular grains, some- 
times with crystal form. The color varies from grayish-white to 
blue and red. Its quality is eminently good. Surface specimens 
from this property often occur associated with blue kyanite. 

Plate VI is reproduced from a photograph of the south side of 
the pit, showing the vein and the stratified chlorite-schists enclos- 
ing it. A geological hammer, with a 14-inch handle, stands in the 
center of the vein, for comparative purposes. 

There seems to be no reason, why it would not pay to work this 
property. The vein is large, unusually rich, and can be easily 
worked for some time, on account of the disintegrated slate of the 



DISTRIBUTION OF CORUNDUM IN GEORGIA. 103 

matrix; and the property is within two miles of Powder Springs, a 
railway station, with an excellent wagon-road between the two 
points. 

PAULDING COUNTY. 

Corundum has been observed in the northeastern and southeast- 
ern corners of Paulding County. 

On lots 533 and 534, 3rd district, 3rd section, and on the farm 
of Mr. William T. Prather, seven miles southeast of Acworth, sur- 
face corundum was found, a few years ago. This led to the pur- 
chase of the property by the Sapphire Valley Company of North 
Carolina. Since this prospecting, which consisted mainly of two 
vertical shafts, no work has been done by the company. 

At the time of survey, these shafts were full of water ; hence, 
the character of the formation penetrated is not known. There are 
no outcroppings close at hand ; and deep disintegration marks the 
area. 

The corundum is dark-blue and deep-pink in color, and is spe- 
cially distinguished by strongly marked parting-planes and by its 
unusual softness. This latter property was overlooked, until a 
wheel, manufactured from it, was found to wear down with extreme 
rapidity under a piece of steel. Mr. E. W. Parker says : — "It is 
supposed that this variety of corundum contains a little water, as it 
is somewhat less hard and more easily cleavable than the common 
variety, known as sand corundum. 1 

Dr. Emerson, in the laboratory of this Survey, has made an analy- 
sis of a specimen of this corundum, with the following result : — 

Sp. Gr._ 4.20 

A1 2 3 94.58 

Si0 2 1.77 

Fe 2 3 0.69 

CaO 0.44 

Water 2.51 

99-99 

1 Mineral Eesources of the United States, 1893, pp. 676 and 677. 



1 04 DISTRIB UTION OF COR UND UM IN GEORGIA. 

If this analysis be compared with the analyses of corundum by 
Dr. Smith, l it will be seen that the percentage of alumina in this 
corundum is very high, and the silica low, while the amount of 
water is lower than several; yet, the hardness of this corundum is 
between 5 and 7- Though readily scratched with a knife, it will 
itself scratch quartz. These facts lead to the suggestion, explana- 
tory of this anomaly, of a possible secondary physical structure, 
which has greatly changed the cohesion. 

CORUNDUM PROPERTIES IN THE VICINITY OF BROWNSVILLE. 

In the notes on Cobb county, it is stated, that a "lead" extends 
from Powder Springs to Brownsville. This is based, in great 
measure, on hearsay evidence, since there has been no attempt at 
development along this line, except at W. B. Turner's in Cobb 
County. The southwest end of this "lead," or the last point, at 
which corundum has been found in the fields, is lot 456, 1st district, 
3rd section, on Jacob W. Meadow's farm, a mile and a half south 
of Brownsville. 

On account of the excellent prospect developed at Turner's, it is 
at least advisable, for the property owners, along this line, to interest 
themselves, in testing the lands, on which they find surface indica- 
tions of corundum, since superficial disintegration and erosion have 
concealed the extent of these corundum-bearing formations; for a 
pretty prospect may be opened up. 

DOUGLAS AND CARROLL COUNTIES. 
Some surface corundum has been found in the vicinity of Villa 
Rica. 

LOT 178, 6TH DISTRICT, DOUGLAS COUNTY, AND LOT 165, 2ND 
DISTRICT, CARROLL COUNTY. 

The lot in Douglas county shows no outcropping; but that in 
Carroll county shows chrysolite and actinolite-talc outcroppings. 
The latter rock is made up of long crystals of actinolite, often as 
long as three inches and over one-third of an inch across, imbedded 
in pure granular white talc. Small veins of asbestus appear in the 
chrysolite. 



1 See page 30. 



DISTRIBUTION OF CORUNDUM IN GEORGIA. IC>5 

On lot 118, 5th district, one and a quarter miles east of Car- 
rollton, the county seat, close to the house of Mr. E. P. Worthy, 
corundum encased in margarite, similar to that found at Gainesville, 
was discovered by the Survey. A very small outcropping of 
chrysolite, with small veins of asbestus, occurs on the south side of 
the road. The corundum, however, was found in his yard on the 
north side of the road. 

HEARD COUNTY. 

LOT 44, I3TH DISTRICT. 

This property belongs to Mr. William A. Hyatt, Central 
Harchee P. O. It contains a small formation of basic magnesian 
rock. From a small ditch across this, Mr. Hyatt uncovered sev- 
eral bowlders, weighing from fifty to one hundred pounds, and con- 
sisting of grayish-white and blue corundum in a matrix of black 
hornblende. Pink scales of margarite are also disseminated through 
the rock. 

The size of the formation does not offer encouraging prospects ; 
but the occurrence of corundum in this association is especially in- 
teresting. 

TROUP COUNTY. 

A short distance northeast of West Point, some northern parties 
prospected last year, over a narrow strip of peridotite rocks, which 
extend from the Chattahoochee River northeast, and outcrop inter- 
mittently, for about five miles. The object of their search was as- 
bestus. 

LOTS 286, 315 AND 316, 5TH DISTRICT. 

The greater portion of the prospecting, mentioned above, was 
done on these lots, belonging to Mrs. N. H. Winston. Corun- 
dum has been picked up occasionally on these lots ; and, from the 
dump of some of the pits, the writer picked up several small pieces 
of corundum, although no vein had been exposed, as well as could 
be determined from the character of the disintegrated material, 
forming the walls of the pits. 



106 DISTRIBUTION OF CORUNDUM IN GEORGIA. 

WALTON COUNTY. 

It will be a matter of surprise to those, who consider the corun- 
dum deposits of Georgia to be confined to a narrow belt, following the 
course of the Chattahoochee River, to learn, that a deposit of corun- 
dum has been discovered in Walton County, some distance to the 
east of this belt. 

LOT 1 60, 3RD DISTRICT. 

Basic magnesian rocks are found at several points in Walton 
county; but, on this lot, the formation is quite wide. The only ex- 
posure is a small outcropping, composed of long, columnar crystals 
of bright-green actinolite in a slight matrix of steatite. At its 
widest point, the formation is about three hundred yards. 

From this lot, over five hundred pounds of excellent block-corun- 
dum have been picked up, and shipped to the market. With the 
exception of a few small trenches, dug for asbestus, no effort at 
testing the property has been made. Nevertheless, the size of the 
property and the surface indications are encouraging for develop- 
ment. 

The property is situated four and a half miles from Monroe, the 
county seat, through which passes the narrow gauge Social Circle 
and Gainesville Railroad. It is on the farm of Mr. George W. 
Breedlove. 



ORIGIN OF GEORGIA CORUNDUM. 

The study of the origin of corundum is still in its infancy. Scientists 
are not yet prepared, to offer more than hypotheses; for they have 
but started on that framework of facts, necessary to adequate theo- 
ries and true conclusions. Hypothesis after hypothesis has been 
advanced; but only a few have sufficient foundation to justify 
second thought. Conservatism in conclusion, based on the few 
facts at our command, is therefore most necessary. 

A single mode of occurrence is observed in Georgia ; that is, 
with the chrysolite formation extending through the Crystalline 



DISTRIB UTION OF COR UND UM IN GEOR GIA. I O 7 

Belt. The types of veins, containing the corundum occurring in 
these bodies, have been mentioned already in a preceding para- 
graph, as have also the geological environments of the chrysolites. 
Concerning the latter, it was noted : — 

(i) That the chrysolite body occurred in gneiss or mica-schist. 

(2) That in every instance, where it was possible to note the re- 
lations, hornblende-gneiss lay close at one side only; not enclosing 
the chrysolite, as stated by Julien 1 to be the case in North Carolina, 
nor in contact, as Chatard says, in his Bulletin. 

(3) That the corundum-bearing veins lie in the chrysolite body, 
close to the contact, and in the vicinity of the hornblende-gneiss. 

It has been observed, that, where all these conditions exist, corun- 
dum is present, often only in small amounts, and sometimes not at all. 
Corundum, therefore, seems to be essentially an accessory mineral, 
its presence being occasioned by an excess of aluminum present in 
the rock-masses, chrysolite, gneiss and hornblende-gneiss. Altera- 
tions of these yield, respectively, magnesium silicates, alkaline 
salts and ferro-silicates, which, together with the carbonic acid of 
the percolating waters, would dissolve the combined aluminum, 
and, on recrystallization, produce all the minerals mentioned as 
associates of corundum, and, in case of an excess of aluminum, 
the aluminum oxide, corundum. Predominence of any of the so- 
lution constituents would give character to the veins ; hence the 
types which have been noted. 

Chatard says : — ' l " Whether the solutions of soda and alumina 
must be heated, in order to effect the production of these minerals, 
is a question, to which, at present, no definite answer can be given; 
but it would seem, that the ordinary subaerial decay of these rocks 
should furnish the necessary solutions. The observations of Becker 
and the experiments of Barus show, that there is considerable doubt, 
as to any production of heat as a result of the kaolinization of feld- 
spar; and, if such is the case with feldspar, it is not likely, that the 
alteration of any of the other mineral species present in these rocks 



1 A. A. Julien ; The Dunyte Beds of North Carolina. Proc. Bos. Soc. Nat. Hist., 
Vol. XXII., 1882, p. 148. 

2 Bulletin 42, U. S. Geological Survey, p. 58. 



108 DISTRIBUTION OF CORUNDUM IN GEORGIA. 

would be attended by any marked rise in temperature. We must 
therefore conclude, that the gneiss can furnish an alkaline solution 
of alumina, and the dunyte, a solution of magnesia, without the pro- 
duction of heat, and, perhaps, without its aid." 

Dr. Genth, from his admirable investigations of corundum, its 
alterations and associate minerals, concludes: — "That, at the great 
period, when the chromiferous chrysolite beds (part subsequently 
altered into serpentine etc.) were deposited, a large quantity of 
alumina was separated, which formed beds of corundum. 

"That this corundum has subsequently been acted upon, and 
thus been changed into various minerals, such as spinel, fibrolite, 
cyanite, and perhaps into some varieties of feldspar; also into tour- 
maline, damourite, chlorite and margarite. 

" That a part of the products of the alteration of corundum still 
exists, in the form of large beds of mica (damourite) and chlorite- 
slates or schists. 

" That another part has been farther altered and converted into 
other minerals and rocks, such as pyrophyllite, paragonite, beauxite, 
lazulite etc." 

The former hypothesis seems more in accordance with known 
facts; yet extended field-work and much laboratory investigation, 
concerning the nature of aluminum, in many instances so evasive, 
must be carried on, in the most careful manner, before we may 
hope to attain a tenable theory. 



CHAPTER VI. 



ECONOMICS. 



History of Corundum Mining in Georgia. 

Value of the Georgia Deposits. 

Preparation and Manufacture. 

Statistics. 

Hints to Prospectors. 



HISTORY OF CORUNDUM MINING IN GEORGIA. 

The history of corundum mining in Georgia is very brief. Only 
two mines have been operated in the State; and, at the present time, 
both are closed. The Laurel Creek mine began active work in 
1880, and shut down in the summer of 1893. During the first 
twelve years, the production was eminently successful, and the 
mining of corundum in Georgia was considered an established in- 
dustry; mining contretemps, however, followed by hard times, 
necessitated the cessation of work. The Track Rock mine is the 
other, which was operated in this State. Mining stopped here, a 
few months prior to the closing down at the Laurel Creek mine. 
Indeed, the period of mining was so brief, that it can be scarcely said 
to have been operated. 

From several localities, corundum, generally picked up from the 
surface, has been shipped in small quantities, and prospecting has 
been carried on, in many places. The number of these prospectors 
attest the interest in the mineral displayed by the citizens. 

VALUE OF THE GEORGIA DEPOSITS. 

Individually, in certain instances, it would be unfair to attempt an 
approximation of the value of the corundum deposits of Georgia. 
In the majority of cases, little, if any, prospecting has been done; 
and, where there has been an attempt at development, such prop- 



HO VALUE OF THE GEORGIA DEPOSITS. 

erties too frequently testify, that the prospectors had little aptitude 
for their work. Again, the formations are often obscured by sub- 
aerial decay and by detritus ; they are also obscured by the cultiva- 
tion of the soil. Until, therefore, the surface limits of the chrysolite 
formations have been defined, and prospecting has revealed the 
veins, whose decay left the insoluble corundum as evidence of their 
presence, just estimates are impossible. 

Regarded as a whole, however, Georgia may well be proud of 
this mineral resource. It is probable, that very few large mines 
will be developed; but, for deposits of a mineral comparatively 
rare, and at present so much sought, for use in the arts, that the 
United States is not able to supply the home demand, the great 
number of small occurrences off er substantial hope for future revenue. 



PREPARATION AND MANUFACTURE. 

In the preparation of corundum, it is first necessary to free it 
from the accompanying gangue. If the gangue is hard, it is 
crushed, and then, like the disintegrated gangue, it is washed in a 
series of sluice-boxes or in a revolving washing-cylinder. The latter 
method of washing was devised by the Track Rock people, and is 
said to be a great improvement over the former method. The 
cylinder is barrel-shaped, and is about ten feet long and six feet 
across the largest part. 1 One end has an open neck attached, to 
permit the shoveling in of the material, while the cylinder is in mo- 
tion. Into this end, also, a steady stream of water is introduced 
by means of a pipe. The other end of the cylinder is closed by a 
wire screen. A trap-door permits the ready removal of the corun- 
dum when cleaned. 

The corundum at Track Rock mine cannot be thoroughly 
cleaned in this way, because of a hard zone of margarite around 
the corundum; hence it is introduced into another machine. This 



1 See Figure 7. 



PREPARATION AND MANUFACTURE. 



Ill 



second machine is a small affair, as seen by figure 8. It contains 
two disks, armed with points, which are revolved with great rap- 
idity. The zonal covering of the corundum, when exposed to this 
treatment, is worn off, almost completely. 



Fig. 7. 




Corundum Washer Used at the Track Rock Mine, Union County, Georgia. 

It is necessary, that all foreign substances be removed, since the 
material, to serve its purposes, must possess practically a uniform 
hardness. This is finally accomplished by further washing, in the 
series of crushings and siftings, which follow, in the reduction of 
the corundum to the various grades or " numbers." In this sub- 
sequent crushing, great care is exercised, to prevent the production 
of flour, since this is of much less value than the coarser grades. 



112 



PREPARATION AND MANUFACTURE. 



The larger portion of corundum thus prepared is used in the man- 
ufacture of corundum wheels. In their manufacture, corundum is 
molded with some definite compound, of such a nature and so pre- 
pared, as to continually present a cutting surface. , 



Fig. 




Ookundum Cleaner Used at the Track Kock Mine, Union County, Georgia. 



STATISTICS. 1 

The product of corundum and emery in the United States is from 
Rabun County, Georgia, Macon and Jackson Counties, North Car- 
olina, Westchester County, New York, Chester County, Pennsyl- 
vania, and Hampden County, Massachusetts. 

1 Mineral Eesources of the United States, 1893. 



STATISTICS. 



"3 



The following table shows the annual product of corundum and 
emery, since 1881: — 

Annual Product of Corundum and Emery since 1881. 



Years. 


Quantity. 


Value. 


Years. 


Quantity. 


Value. 


1881 


Short tons. 
500 
500 
550 
600 
600 
645 
600 


$80,000 
80,000 
100,000 
108,000 
108,000 
116,190 
108,000 


1888 


Short tons. 
589 
2,245 
1,970 
2,247 
1,771 
1,713 


$ 91,620 
105,567 


1882 


1889 


1883 


1890 


89,395 
90,230 
181,300 
142,325 


1884 


1891 


1885 


1892 


1886 


1893 


1887 







Emery Imported into the United States from 1867 to 1893, Inclusive. 



Years ended— 


Grains. 


Ore 01 


rock. 


Pulverized or 
ground. 


Other 
manufac- 
tures. 


Total 


Quantity. 


Value. 


Quantity. 


Value. 


Quantity. 


Value. 


value. 


June 30 


, 1867.... 


Pounds. 




Tons. 

428 
85 

964 

742 

615 
1,641 

755 
1,281 

961 
1,395 

852 
1,475 
2,478 
3,400 
2,884 
2,765 
2,447 
4,145 
2,445 
3,782 
2,078 
5,175 
5,234 
3,867 
2,530 
5,280 
5,066 


$ 14,373 
4,531 
35,205 
25,335 
15,870 
41,321 
26,065 
43,886 
31,972 
40,027 
21,964 
38,454 
58,065 
76 481 
67.781 
69,432 
59,282 

121,719 
55,368 
88,925 
45,033 
93,287 
88,727 
97,939 
67,573 
95,625 

103,875 


Pounds. 

924,431 

834,286 

924,161 

644,080 

613,624 

804,977 

343,828 

69,890 

85,853 

77,382 

96,351 

65,068 

133,556 

223,855 

177,174 

117,008 

93,010 

513,161 

194.314 

365,947 

a 144,380 


$ 38,131 
33,549 
42,711 
29,531 
28,941 
36,103 
15,041 
2,167 
2,990 
2,533 
3,603 
1,754 
4,985 
9,202 
7,497 
3,708 
3.172 
21,181 
8,789 
24,952 
6,796 




$ 52,504 
38,080 




1868.... 










1869 ... 








77,916 




1870... 








54.866 




1871 






44,811 




1872 ... 






77,424 




1873 ... 
1874.... 
1875.... 
1876.... 
1877 ... 
1878.... 
1879.... 
1880.... 
1881 .... 
1882.... 
1883 ... 
1884.... 
1885..., 
1886.... 
1887 ... 
1888.... 
1889.... 
1890 ... 
1891.... 
1892.... 
1893 ... 


610,117 
331,580 
487,725 
385,246 
343,697 
334 291 
496,633 
411,340 
454,790 
520,214 
474,105 
143,267 
228,329 
161,297 
367,239 
430,397 
503,347 
534,968 
90,658 
566,448 
516,953 


$ 29,706 
16,216 
23,345 
18,999 
16,615 
16,359 
24,456 
20,066 
22,101 
25,314 
22,767 
5,802 
9,886 
6,910 
14,290 
16,216 
18,937 
20,382 
3,729 
22,586 
20,073 


$ 107 
97 
20 
94 


70,919 
62,366 
58,327 
61,653 

42,182 




34 


56,601 
87,506 


Dec. 81, 


145 

53 
241 

269 

188 

757 

851 

2,090 

8,743 

111,302 

5,046 


105,894 
97,432 
98,695 
85.49C 

148,890 
74,800 

121,638 
68,209 

118,246 








218,966 








123,367 








71,302 








2,412 
3,819 


120,623 








127,767 











a To June 30, only ; since classed with grains. 



114 HINTS TO PROSPECTORS. 



HINTS TO PROSPECTORS. 



" Show me corundum," an old corundum prospector says, " and 
I will show you corundum. " The suggestiveness of this remark 
is at once apparent to any person, who has made a search for co- 
rundum. In other words, prospectors for corundum should be fa- 
miliar with its associates. The knowledge, that chalcedony is an 
accompaniment of corundum, had aided the prospector, just quoted, 
in finding some of the prettiest prospects in Georgia. 

Professor Jackson, 1 in 1864, finding margarite at an iron mine in 
Chester, Mass., predicted the occurrence of emery, which was dis- 
covered shortly after. At Rabun Gap, the writer discovered a co- 
rundum vein, by the presence of a thin seam of compact, scaly 
chlorite ; in Habersham, his attention was attracted to a small ag- 
gregate of black hornblende and feldspar ; other specimens of the 
same were soon found containing corundum. At Gainesville, he lo- 
cated the corundum, found in the stream, by margarite-mantled 
bowlders on the neighboring hill; and, from the presence of marga- 
rite, he discovered corundum east of Carrollton, in Carroll county. 

Being assured of the presence of corundum by the associate min- 
erals, and failing to find any specimens on the surface by simple in- 
spection, proceed in the same manner as for gold, that is, pan the 
gravel. Good testing in this way should give favorable results; 
otherwise, there is little ground, on which to base hopes for a de- 
posit worthy of further investigation. If corundum is disclosed,, 
the next thing in order is to locate the vein or veins. 

To accomplish this, it will be necessary, first, to determine the 
boundaries of the chrysolite formation; in other words, its contact 
with the inclosing formations. In some instances, the contact with 
these bodies will be apparent; in others, where the formation is ob- 
scured in ways previously noted, this may be accomplished, either 
by running a furrow, or, if necessary, a ditch, across the uncertain 
portions, at right angles to the trend or strike of the formation. 

1 Letter to Dr. J. L. Smith from Professor C. T. Jackson ; Scientific Researches ; 
J. Lawrence Smith, p. 43. 



HINTS TO PROSPECTORS. I I 5 

Finally, the contacts determined, confine work closely to those 
points near hornblende-gneiss, and keep a sharp watch for altera- 
tion and associate minerals of corundum. This caution is especially 
required, where the rocks are badly disintegrated. 

The occurrence of corundum in the contact bodies has been ob- 
served by certain workers in North Carolina; hence, it will be ad- 
visable to also scan these critically. 






CHAPTER VII. 



AMERICAN LITERATURE ON CORUNDUM. 

Very little has been published about corundum, either as to its 
mode of occurrence, or as to its origin ; and scarcely anything, 
except the most general statements, can be found in regard to the 
deposits in Georgia. The American literature on corundum is as 
follows : — 
Adams, J. H. — " Corundum of Pelham, Mass., with Black Mica in 

Feathered Masses." 

Am. Jour. ScL, 2nd Series, Vol. XLIX, p. 272. 
Blake, W. P. — " Corundum in Crystallized Limestone at Union, 

Sussex County, N. J." 

Am. Jour. Sci., 2nd Series, Vol. XIII, 18^2, p. 116. 
Cooke, J. P. — " Corundum Regions of North Carolina and Georgia." 

Am. Jour. Sci., yd Series, Vol. IX, 1874, VV- 48-49. 
Chatard, T. M. — The Gneiss-Dunyte Contacts of Corundum Hill, 

N. C, in Relation to the Origin of Corundum." 

Extract from Bull. No. 42, U. S. Geological Survey. 
Chatard, T. M.— " Corundum and Emery." 

Mineral Resources of the United States, 1883-84, 
pp. 714-720. 
Chatard, T. M.— " Corundum." 

Mineral Resources of the United States, 1885, pp. 429-432. 
Dickson, John. — " Notes." 

Am,. Jour. Set, 1st Series, Vol. Ill, 1821, pp. 7 and 229-230. 
Dana, E. S. — « Corundum." 

System of Mineralogy of Jas. D. Dana; sixth edition; 
1892, pp. 210-213. 
Gannett, Henry — " Corundum and Emery." 

Mineral Resources of the United States, 1892, pp. 476-477. 



AMERICAN LITERATURE ON CORUNDUM. 117 

Genth, F. A. — "Corundum, Its Alterations and Associated Min- 
erals." 
Trans. Am. Phil. Soc, Sept., 1873. 

Genth, F. A. — " Corundum." 

Trans. Am. Phil. Soc, July, 1874. 

Genth, F. A. — "Contributions to Mineralogy." 
Trans, Am. Phil. Soc, Aug., 1882. 

Genth, F. A. — " Contributions to Mineralogy." 

Am. Jour. Sci., 3rd Series, Vol. XXXIX, i%go,pp. 47-50. 

Hunter, C. L.— "Corundum in Gaston County, N. C." 
Am. Jour. Sci., 2nd Series, Vol. XV, p. 373. 

Hunt, T. S.— Royal Society of Canada, Vol. II, Sec. Ill, 1884, 

PP. 37-38. 
Jencks, C. W. — "Corundum of North Carolina." 

Am,. Jour. Sci., 3rd Series, Vol. Ill, 1873, ^p.301-302. 

Quar. Jour. Geol. Soc, Vol. XXX, 1874, PP- 3°3-3°6. 
Julien, A. A. — " The Dunyte Beds of North Carolina." 

Proc Boston Soc. Nat. Hist., Vol. XXII, Dec, 1882. 
Kerr, W. C. — " Corundum of North Carolina." 

Geol. Sur. N. C, Vol. I, Supplement, 1875, PP- 64-65. 
Paret, T. D. — " Emery and Other Abrasives." 

Jour. Frank. Inst., Vol. CXXXVII, 1894, pp. 353-372 
and 421-438. 
Parker, E. W. — " Emery and Corundum ." 

Mineral Resources of the United States, 1893. 
Raborg, W. A. — " Corundum." 

Mineral Resources of the United States, 1886. 
Raymond, R. W. — " The Jencks Corundum Mine, Macon County, 

North Carolina." 

Trans. Am. Inst. Min. Eng., Vol. VII, 1878,^.83-90. 
Seal, T. S. — " Corundum in Chester County, Pa." 

Am. Jour. Sci., 2nd Series, Vol. XI, pp. 267 et seq. 
Shepard, C. U. — " On the Corundum Region of North Carolina 

and Georgia." 

Am. Jour. Sci., 3rd Series, Vol. IV, 1872, pp. 109-175. 



1 1 8 A MERICAN LITER A TURE ON COR UND UM. 

Silliman, B. — " Corundum etc., at Unionville, Pa." 

Am. Jour. ScL, 2nd Series, Vol. VIII, p. 384. 
Smith, C. D. — " Corundum and Its Associate Rocks." 

" Geology of Western North Carolina." 

Geol. Sur., N. C, Vol. I, Appendix D, 1875. 
Smith, C. D. — " Corundum." 

Geol. Sur., N. C, Vol. II, 1881, pp. 42-43 
Smith, J. L. — Memoirs on Emery. 

Scientific Researches, 1851,^. 1-53. 

Comptes Rendus, Vol. 31. 

Annals des Mines (XIV) Vol. XVIII, p. 259. 

Am. Jour. ScL, 2nd Series, Vol. X, p. 354. 

Am. Jour. ScL, 2nd Series, Vol. II, pp. 53-56, 

Am. Jour. ScL, 2nd Series, Vol. XLII. 

Am. Jour. ScL, 3rd Series, Vol. VI, 1873, p. 180. 
Trautwine, J. C— "Corundum with Diaspore,Culsagee Mine, N. C." 

Jour. Frank. Inst., Vol. XCIV, p. 7. 
Wadsworth, M. E. — « N. C. Chrysolite etc." 

Liihological Studies, 1884,^. 118-119. 
Willcox, J. — " Corundum in North Carolina." 

Proc. Acad. Nat. ScL, Phila., 1878, p. 225. 
Williams, G. H. — Norites of the " Courtlandt Series." 

Am. Jour. ScL, 3rd Series, Vol. XXXIII, 1887, p. 194. 
Various Writers — "Corundum in North Carolina." 

Pop. ScL Mo., Feb., 1874. 

Second Geol. Sur., Pa. (B), 1875, P- 3 1 - 

The Commonwealth of Ga., 1885, £>. 139. 

Agricultural Report of South Carolina, i88z,mapandp. 137. 






CHAPTER VIII. 



SUPPLEMENTARY. 



NATURAL AND ARTIFICIAL ABRASIVES. 

STATURAL ABRASIVES. 
Pumice. 

Infusorial Earth. 
Tripoli. ' 
buhrstones. 
Grindstones. 
Oilstones and Whetstones. 

AKTIFICIAL ABRASIVES. 
Crushed Steel. 
Carborundum. 



NATURAL ABRASIVES. 

PUMICE. 

Pumice is a spongy, vesicular variety of feldspathic lava, which 
owes its froth-like appearance to the tumultuous escape of gasses 
and steam, while it is yet in a viscous state. The bulk of pumice, used 
in this country, comes from Italy. Large deposits of it, found in 
California, are used to supply the demand on the Pacific coast. 
Quotations in New York for wholesale lots are: — 

Select lumps @ $ .03}^-$ .15 per pound. 

Original cakes @ 01 y 2 - .02 " " 

Powdered, pure, @ 01^- .01^ " " 

Pumice is used principally for marble polishing. 

INFUSORIAL EARTH. 

Infusorial earth is composed of the extremely minute siliceous 
•diatoms, the lowest order of unicelled plants. They form beds 



120 



NATURAL ABRASIVES. 



upwards of thirty feet in thickness; and, according to Ehrenberg, a 
cubic inch of the material contains 40,000,000,000 shells. On ac- 
count of its soft, chalky consistency, it is adapted particularly for 
fine polishing. Formerly infusorial earth was used chiefly as an 
absorbent of nitro-glycerine, in the manufacture of dynamite and 
other nitro-glycerine explosives, 25 per cent, of the product being 
infusorial earth. Now, in addition to abrasive purposes, it is used 
in the manufacture of soap; and it is coming into use in the manufac- 
ture of enamel brick, terra-cotta, fancy tiles and glazed-ware 
goods. 

In the United States, it is mined chiefly in Maryland, Connecti- 
cut, Nevada, New Hampshire and New Jersey. 

The following table shows the annual production of infusorial 
earth since 1880: — 





Production of Infusorial Earth from 1880 to 


1893. 




Years. 


Short tons. 


Value. 


Years. 


Short tons. 


Value. 




1,833 
1,000 
1,000 
1,000 
1,000 
1,000 
1,200 


$45,660 
10.000 
8,000 
5,000 
5,000 
5,000 
6,000 


1887 


3,000 
1,500 
3,466 

2,532 


$15,000 


1881. 


1888 

1889 

1890 


7,500 


1882 


23,372 


1883 


50,240 
21,988 


]884 


1891 


1885 


1892 




43,655 




1893 




22,582 












TRIPOLI. 

" Tripoli " is a term applied to a siliceous earth, which is mined 
extensively in Newton county, Missouri. It was first thought to be 
a species of decomposed quartz; but it is now considered a disinte- 
grated siliceous limestone, from which the carbonate of lime has 
been leached out. The formation in Newton county is from ten to 
twenty feet thick, and covers over eighty acres, being the largest 
known deposit in the world. 

On account of its porosity and absorptive qualities, the product 
is manufactured into water-filters and ink-blotters, which serve 
their respective purposes admirably. On account of its lack of 
iron, coarse sand or grit, it makes an exceedingly fine abrasive, 
when powdered, possessing a sharp cutting grain, that will polish 



NATURAL ABRASIVES. 121 

silver etc., without scratching. It is also used in the manufacture 
of soap and other cleansing preparations. 

Henderson writes: — Ut A tripoli or rotten stone, of excellent quality 
as a polishing materia], is abundant near Dalton, and is found also 
in many other localities in this part of the State." Such properties 
should be investigated. 

"The output from the mine" (at Carthage, Missouri,) "in 1892 
was nearly 2,000,000 pounds, or 1,000 short tons of powdered ma- 
terial, and between 15,000 and 20,000 finished pieces of filter goods, 
the total value of which is estimated at about $30,000." 2 Work 
was continued on the property in 1893, and the output increased 
over that of 1892 about 25 per cent." 3 

BUHRSTONE. 

A " buhrstone " is a cellular rock, very siliceous and exceedingly 
compact. The Tertiary deposits of the French basin have always 
afforded the best buhrstones, although American stones have 
served as well, for the coarser cereals. 

In Henderson's report, 4 we find that the buhrstone, found in 
many portions of Southern Georgia, " has been pronounced by ex- 
perts, as, in all particulars, equal to the best quality of French buhr. 
Also, that it exists in large quantities along and near the Savannah 
river, and at other points convenient to transportation. The stone 
varies from a light-gray to a reddish-brown color." 

The buhrstone of Georgia occurs in the "Buhrstone Division" 
of the Middle Miocene series. 5 

This division extends from the Chattahoochee river at Early 
county, northeast to Burke and Screven counties, and on into South 
Carolina. According to Dr. Spencer, the extent of the buhrstone 
is limited in the mass, and is not confined to a single horizon. 

The " roller process " in large mills has caused a decline in the 

1 Commonwealth of Georgia, Part 1, 1885, p. 139. 

2 Mineral Kesources of the United States, 1892, p. 753. 

3 Mineral Kesources of the United States, 1893, p. 679. 

4 The Commonwealth of Georgia, Part I, 1885, p. 138. 

5 First Keport of Progress, Geol. Surv. Ga., 1890-91 ; J. W. Spencer; p. 149. 



122 



NATURAL ABRASIVES. 



production of buhrstones, and this decrease will probably continue, 
on account of the introduction of emery-rock millstones. 

The following table shows the value of buhrstones produced in 
the United States since 1880: — 

Value of Buhrstones Produced in the United States since 1880. 



Years. 


Value. 


Years. 


Value. 


1880 


$200,000 
150,000 
200,000 
150,000 
150,000 
100,000 
140,000 


1887 


$100,000 
81,000 


1881 


1888 


1882 


1889 


35,155 
23,720 


1883 


1890 

1891 


1884 


16,587 
23,417 
16,639 


1885 


1892 


1886 


1893 







The following table of imports shows, that the decline in the buhr- 
stone industry has not been confined to stones of domestic produc- 
tion : — 



Value of Buhrstones and Millstones Imported into the United States from 1868 to 1893. 






Made 








Made 




Years Ended— 


Rough. 


into Mill- 
stone. 


Total. 


Years Ended— 


Rough. 


into Mill- 
stone. 


Total. 


June 30, 1868 


$ 74,224 


$ 


$ 74,224 


June 30, 1881 


$ 100,417 


$ 3,495 


$ 103,912 


1869 


57,942 


2,419 


60,361 


1882 


100,287 


747 


104,034 


1870 


58,601 


2,297 


60,898 


1883 


73,413 


272 


73,685 


1871 


35,406 


3,698 


39,104 


1884 


45,837 


263 


46,100 


1872 


69,062 


5,967 


75,029 


1885. ... 


35,022 


455 


35,477 


1873 


60,463 


8,115 


68,578 


Dec. 31, 1886 


29,273 


662 


29,935 


1874.. .. 


36,540 


43,170 


79,710 


1887 


23,816 


191 


24,007 


1875 


48,068 


66,991 


115,059 


1888 


36,523 


705 


37,228 


1876 


37,759 


46,328 


84,087 


1889 


40,432 


452 


40,884 


1877 


60,857 


23,068 


83,925 


1890. ... 


32,892 


1,103 


33,995 


1878 


87,679 


1,928 


89,607 


1891 


23,997 


42 


24,039 


1879. . . 


101,484 


5,088 


106,572 


1892 


33,657 


529 


34,186 


1880. . . 


120,441 


4,637 


125,072 


1893... . 


29,532 


729 


30,261 



GRINDSTONES. 

The Mineral Resources of the United States reports the main 
output of grindstones to be from Ohio and Michigan. The grind- 
stones from Ohio are made from the sandstone of the geological 
formation known as Berea Grit. This underlies large areas in the 
northwestern part of Ohio, and takes on local names in different 
sections. Its color varies, in different localities, from white, brown- 
ish-white, grayish-white to yellowish- white; and its structure, from 
a fine and sharp grit to a coarse grit. The Michigan sandstone is 
blue, and possesses a fine, sharp grit. Both are used for sharpen- 
ing edge tools. 



NATURAL ABRASIVES. 



123 



The sandstones of Georgia have, up to the present, only local 
importance, although, for grindstone purposes, their fitness has been 
known for sometime. Henderson speaks of the itacolumite, or 
flexible sandstone, in certain localities, as affording " a suitable ma- 
terial, both for whetstones and grindstones, as do also some of the 
sandstones of Taylor's Ridge and of Chattooga and Lookout 
mountains." l 

The annual production, since 1880, has been as follows: — 

Value of Grindstones Produced in the United States, 1880 to 1893. 



Years. 


Value. 


Years. 


Value. 


1880 


$500,000 
500.000 
700,000 
600,000 
570,000 
500,000 
250,000 


1887 

1888 


$224,400 
281,800 
439,587 
450,000 
476,113 
272,244 
338,787 


1881 


1882 


1889 


1883 


1890 


1884 


1891 


1885 


1892 


1886 


1893 







Grindstones Imported and Entered for Consumption in the United States, 1868 to 1893, 

Inclusive. 



Years ended— 


Finished. 


Unfinished or rough. 


Total. 


Quantity. 


Value. 


Quantity. 


Value. 


value. 


June 30, 1868 


Long tons. 


$ 25,640 
15,878 
29,161 
43,781 
13,453 
17,033 
18,485 
17,642 
20,262 
18,546 
21,688 
24,904 
24,375 
30,288 
30,286 
28,055 


Long tons. 


$ 35.215 
99,715 
96,444 
60,935 
100,494 
94,900 
87,525 
90,172 
69,027 
58,575 
46,441 
52,343 
51,899 
56,840 
66,939 
77,797 


$ 60,855 
115,593 
125,605 
104,716 
113 947 


1869 






1870 






1871 


385 
1,202 
1,437 
1,443 
1,373 
1,681 
1,245 
1463 
1,603 
1,573 
2,064 
1,705 
1,755 


3,957.15 
10,774.80 
8,376.84 
7,721.44 
7,656 17 
6,079.34 
4,979.75 
3,669.41 
4,584.16 
4,578.59 
5,044.71 
5,945.61 
6,945.63 


1872 


1873 


111,933 
106,010 
107 814 


1874 


1875 


1876 

1877 


90,189 
77,121 
68,129 


1878 


1879 


77,247 
76,274 
87,128 
97,225 
105,852 
a86,286 
50,579 
39,149 
50,312 


1880 


1881 .. 

1882 


1883 


1884 


1885 










Dec. 31, 1886 










1887 










1888 










51,755 
57,720 
45,115 
21,028 
61,052 
59,569 


1889 










1890 










1891 










1892 










1893 























a Since 1884 classed as finished or unfinished. 



1 The Commonwealth of Georgia, Part I, 1885, p. 139. 



124 NATURAL ABRASIVES. 

OILSTONES AND WHETSTONES. 

" The most important whetstone grit, known in the State, is the 
novaculite of Lincoln county." l The most important stone found 
in the United States for oilstones and whetstones is " novaculite," 
which is mined principally in Arkansas. Its discovery in Arkansas, 
as a material fitted for abrasive purposes, was made sometime prior 
to 1818, and, since that time, its suitableness has become more and 
more apparent, as shown by foreign export. The term novaculite 
(novacula, a razor) is applied to a class of exceedingly hard, fine- 
grained, siliceous rocks, which are particularly adapted to whetstone 
purposes. The cutting power of novaculite is due, according to 
Griswold, 2 to the presence of innumerable small cavities — rhombic 
in shape, and resulting evidently from the leaching out of lime in the 
form of calcite — whose sharp edges, partially assisted by the fre- 
quent occurrence of large siliceous grains, with jagged outline, go 
to make up the abrasive face. 

The Georgia occurrences of novaculite are found in McDuffie, 
Oglethorpe, Troup, Meriwether, Heard and Lincoln counties. In 
Lincoln county, it occurs as a low hill two miles from Lincoln 
Court-house, and projects nearly vertically from the ground, over an 
area of four or five acres. It has several colors. Where exposed, 
it is straw-colored; below the surface, it is greenish- white. This 
is the occurrence, of which Commissioner Henderson speaks, in 
such strong terms. It has been much used, locally; but it has 
never been quarried to any extent; whether on account of its inferi- 
ority, or for lack of investigation, is not known. Its presence, how- 
ever, within the State is worthy of notice. 

Included in the productions of the United States " are the two 
grades of novaculite from Arkansas, known as the Arkansas and 
the Wachita stone ; the fine-grained sandstone of Orange County, 
Indiana, known as Hindostan or Orange county stone; a gray sand- 
stone, known as Lake Superior stone, from Cortland County, New 
York; Chocolate stone from Lisbon, New Hampshire; and scythe- 

1 The Commonwealth of Georgia, Part I, 1885, p. 139. 

2 Annual Report, Arkansas Geol. Surv., 1890, Novaculites; by Griswold; p. 90. 



NATURAL ABRASIVES. 



125 



stones made from Indian Pond and Lamoille sandstones, quarried 
in Grafton County, New Hampshire, and Orleans County, Vermont, 
and from Berea, Ohio, " grit." 

Production of Whetstones etc., by the Pike Manufacturing Company in 1892 and 1893. 



Kinds. 



Wachita stone pounds. 

Arkansas stone do 

Labrador stone do 

Hindostan stone do 

Sandstone do. .. 

Chocolate stone do — 

Scythestones gross. . 



Total 



pounds, 
gross. 



1892. 



Output. Value 



400,000 

20,000 

500 

300,000 

100,000 

20,000 

16,000 



856,500 
16,000 



60,000 

12,000 
50 

15,000 
2,000 
2,000 

50,000 



J 141,050 



1893. 



Output. Value 



300,000 
12,000 
200 
250,000 
100,000 
20,000 
13,000 



682,000 
13,000 



$ 45,000 

12,000 

20 

13,000 

2,000 

2,000 

40,000 



114,020 



Estimated Exports of Whetstones etc., in 1892 and 1893. 



Kinds. 



: Scythestones gross. 

Wachita stone pounds. 

Arkansas stone do. . . 

Hindostan stone do. .. 

Sandstone 



Total value. 



1892. 



Amount. Value 



8,000 

150,000 

9,000 

75,000 



$ 20,000 
20,000 
12,250 
2,250 



54,500 



1893. 



Amount. Value 



8,000 
180,000 

8,000 

100,000 

50,000 



$ 19,000 
21,000 
10,500 
3,500 
1,000 



55,000 



Estimated Imports of Whetstones etc., in 1892 and 1893. 



Kinds. 


1892. 


1893. 


Amount. 


Value. 


Amount. 


Value. 


Turkey stone 


pounds.. 

do 


1,000 

8,000 

1,000 

50 


$ 200 

800 

2,000 

300 

None. 

1,000 


1,000 

4,000 

1,000 

25 

30,666 


$ 200 
400 


Razor hones. 


dozen. .. 


1,500 
150 








50,000 


500 












4,300 




2,750 









126 ARTIFICIAL ABRASIVES. 

ARTIFICIAL ABRASIVES. 

CRUSHED STEEL. 

A prominent corundum mine owner and manufacturer informs the 
Survey, that the most prominent usurper of the corundum industry- 
is "crushed steel." On account of the cheapness of the product, and 
the variety of uses, to which it may be put, it is for the present re- 
placing much corundum and emery in the arts. 

A concise description of this is given in the Mineral Resources of 
the United States, 1892, as follows: — "Another recent invention in 
the line of abrasives, to which attention has been called, by an inter- 
esting exhibit at the Columbian Exposition, is "crushed steel," man- 
ufactured by the Pittsburg Crushed Steel Company, limited, of 
Pittsburg, Penn. This product is obtained from crucible steel, highly 
carbonized, and made crystalline in structure, by manipulation in 
furnaces and chemical bath treatment. It is then reduced to small 
crystals, by crushing under heavy machinery, after which it is 
assorted into sizes by a system of sieves. The larger sizes, which 
vary from about the size of a No. 2 bird shot to one-fortieth of an 
inch, are classed as crushed steel proper, and used for sawing stone, 
particularly those varieties possessing hard and gritty qualities, such 
as granite, sandstone, marble etc. Grains, which pass through 
sieves, ranging from forty to one hundred and fifty meshes to the 
inch, are classed as "steel emery," and are used upon rubbing beds, 
and for polishing purposes. The finest product is, by an oxidizing 
process, manufactured into putty-powder and rouge, for polishing 
marbles, granites, agate and glass. 

"The crystals of crushed steel and steel emery present sharp,, 
cutting edges, having about the same angles as quartz, when 
crushed. They are exceedingly hard, and are more effective, 
under the saw blades and on the rubbing bed, than sand. The ef- 
fectiveness of crushed steel and steel emery is due to the fact, that 
the crystals do not wear away and become smooth. A grain of 
crushed steel, under the microscope, presents a series of crystals; 
and, if sufficient force be applied, they are detached; but they main- 



ARTIFICIAL ABRASIVES. 1 27 

tain their crystalline form and abrasive qualities. For this reason the 
material can be used a great number of times, and in order to effect 
the greatest economy in its use, the manufacturers of crushed steel 
have also invented automatic attachments for saw gangs and rub- 
bing beds, by which the steel once used is saved and returned. The 
efficacy of these products — crushed steel, steel emery, and the 
putty-powder and rouge — has been attested by stone-workers and 
manufacturers of lenses." 

CARBORUNDUM. 

An artificial abrasive, which has been attracting unusual atten- 
tion lately, is termed by its inventor, Mr. E. G. Acheson, of Monon- 
gehala City, Pa., " Carborundum." The object of the invention 
was to produce a substitute for corundum and other abrasive ma- 
terials. Reports as to its success have been contradictory. As a sub- 
stitute for corundum, it thus far fails, mainly (1) because the man- 
ufacturers are not yet able to produce it as cheaply, and (2) because 
it lacks the toughness, being extremely brittle. 

The description of carborundum, its manufacture, properties and 
uses, as given by the Committee on "Science and the Arts," of 
the Franklin Institute, 1 is as follows: — 

" The method of manufacture consists in general, in subjecting 
to an extremely high temperature, and for a considerable time, 
mixtures of carbon with silica, or siliceous materials, and a suit- 
able flux. 

" The inventor finds, that the heat, generated by an electric cur- 
rent, affords him the most efficient conditions, for securing the high 
temperatures, needed to bring about the reaction, and accordingly 
states his preference for the use of the electric furnace. 

" The following general description will serve to explain the 
mode of operation : — 

" An intimate mixture of carbon and sand is introduced into a 
rectangular box of brick or fire-clay, constituting the furnace 
chamber, the mixture being so placed, as to surround a core of 
granular carbon. Into each end of the chamber project several 

1 Journal of the Franklin Institute, Vol. CXXXVII, 1894, pp. 402-407. 



128 



ARTIFICIAL ABRASIVES. 



rods of the carbon, making connection with the core, and, through 
these rods and the core, is passed a current, sufficient in quantity, 
and for a sufficient length of time, to fuse the contained silica, and 
bring about its subsequent combination with a portion of the car- 
bon, to form a new substance, a silicide of carbon, to which the 
name of carborundum has been given. 



Fig. 9. 




Electrical Furnace eor the Manufacture of Carborundum. 



" Upon removal from the furnace, the carborundum is found as 
a porous cinder-like mass, formed of groups of small, glittering 
crystals of yellowish-green, bluish-green, or blue color, surrounded 
by more or less coherent masses of partly altered carbon. 

" The separation of the carborundum from the other constitu- 
ents of the mass is first effected, as completely as may be, by hand. 
The selected material is washed in water, then treated with acid, to 
remove soluble impurities (iron, alumina, lime etc.), again washed, 
then dried and crushed. By this means the individual crystals are 
separated, and the purefied material is then separated into com- 
mercial sizes of different degrees of fineness, by a process of float- 



ARTIFICIAL ABRASIVES. 



129 



ation in a current of water, the several grades being thus auto- 
matically collected in separate receptacles. 

"An analysis of the product thus formed shows, that it is a com- 
pound thus far new in chemistry, a combination of one atom of 
silicon with one atom of carbon, or, in chemical terms, a silicide of 
carbon, having the formula SiC. The re-action involved consists 
in the withdrawal, by the carbon, of two atoms of oxygen from the 
silica of the sand or clay, and the combination of the nascent silicon 
with a portion of the surplus highly heated carbon, according to the 
equation, 

Si0 2 -h3C=SiC + 2CO. 

"It is well known to chemists, that the formation of silicide of 
carbon, by the direct reduction of silica with carbon, has hitherto 
been impossible, at any temperature attainable in the laboratory. 
By the employment of the heating effect of the electric arc, in a 
furnace of the simple construction described above, in which the 

Fig. 10. 



\_j LSocKee c ffUctrm t 




Longitudinal section through furnace before passage of current. 



heat can be confined, the temperatures obtainable are so much 
greater, than can be realized by any other known methods, that 
re-actions heretofore deemed impossible are readily effected. In 



13° 



ARTIFICIAL ABRASIVES. 



the hands of Moissan and others, the electric furnace has lately 
been made to yield results of a nature, as extraordinary and un- 
looked-for, as those, which followed upon the first application by 
Davy of the voltaic battery, to effect chemical decompositions. In 
employing the electric furnace method, therefore, to bring about 
the desired results, Mr. Acheson deserves the credit of having ap- 
plied the only method, by which it could have been successfully 
accomplished. 

"At this point, it is worthy of notice that Moissan, whose recent 
experimental work with the electric furnace has greatly extended 
our knowledge of chemical re-actions, taking place at enormously 
high temperatures, produced this same compound (SiC), and de- 
scribed its properties, in a communication presented to the French 
Academy at the session of October, 1893 ; also, that Schutzenberg- 
er formed it, by the combined reducing action of carbon and sili- 
con on silica. Mr. Acheson's results were obtained and duly an- 
nounced, however, before the publication, by these investigators, of 
their results. 

Fig 11. 




Section through furnace before passage of current. 



" The interest attaching to this compound, because of its nov- 
elty and the mode of its production, is greatly increased by the 
remarkable properties, which it exhibits. Those properties, which 
are more particularly referred to, are the following: — 



ARTIFICIAL ABRASIVES. 



131 



"Permanence.— Being formed at an enormously high tempera- 
ture, it is natural to anticipate, that it would be stable, at all temper- 
atures below that of its formation; but, in addition to this stability. 



Fig. 12. 





<*g§i 


B^ 






-,, , 




fe 






Carborundum, not crystallized 








Carborundum crystals -* 


-T-JB 


BR* 








— J — km- 








; bj&smm 








pS5®$& 




















f f" 1 








1 






III 1 


1 1 




1 1 






1 1 1 


1 1 




1 1 








III 




1 












1 ' 1 ' 1 1 


1 




1 . 1 1 1 . 



Section through furnace after passage of current. 



it appears to be capable of resisting many of the most powerful 
chemical reagents. The only reagents, that appear to be capable 
of decomposing it readily, are the caustic and carbonated alkalies, 
in the state of fusion. 

"Infusibility. — The substance appears to rank with the most in- 
fusible substance known, yielding only to the heat of the electric 
furnace. 

"Hardness. — In this quality, the substance approaches, if, indeed, 
it does not equal the diamond, the hardest of known substances. 
This quality is one, which, at first, would not be readily recognized, 
being masked by the brittleness of the crystals. 

" It is upon its hardness, that the present and prospective appli- 
cations of the material are based. It is, in brief, as an abrasive 
material, for grinding and polishing metals, glass and precious 
stones, that carborundum has been found to possess decided merits; 
and, when its unique physical characteristics are so thoroughly 
understood, that they may be utilized to the best advantage, the 
material, in all probability, will rank among the most valuable ab- 
rasives known to the arts. It was first usefully applied, for the 
cutting and polishing of diamonds and other precious stones, and, 



I3 2 ARTIFICIAL ABRASIVES. 

from reliable evidence presented in the course of this investigation, 
its cutting qualities will bear comparison with those of diamond- 
dust. It is reported to be specially useful for polishing such gems, 
and one of the members of the sub-committee charged with this 
investigation, having tested the merits of the material on various 
gems, reports very favorably upon it. 

" It is used in considerable quantity, in the grinding of the glass 
stoppers and bulbs of the new Westinghouse electric incandescent 
lamps, for which service it answers very satisfactorily. It is found 
very efficient in certain finishing operations in machine work, as, for 
example, for brass valve grinding. Of late, it has been introduced 
in the form of small wheels, discs and points, for use in dentistry, in 
place of the corundum tools in general use ; and, finally, it has just 
been introduced in the market in the form of wheels of large size, 
for general grinding and cutting purposes in machine work, as a 
substitute for emery wheels. 

" The sub-committee charged with this investigation was supplied 
with a considerable number of samples of the material, in powder 
form and made up into wheels, with which to make trial of its use- 
fulness. The results are given in what follows : — 

" A number of wheels, of the sizes and grades indicated as most 
suitable for certain special uses, were sent to a number of machine 
shops, whose proprietors had expressed their willingness to test 
them. (Their reports form part of the record of this case, and are 
accessible for reference.) 

" The results of the tests of these large wheels were very con- 
tradictory, the wheels being pronounced very satisfactory by some, 
and being condemned by others; but, in the main, the verdict was 
unfavorable. The absence of concordance in these results would 
seem to indicate the existence of faulty methods of manufacture, 
possibly the use of unsuitable binding material. It is certainly not 
unreasonable to assume, that, when more experience has been gained 
with carborundum, and its peculiar physical qualities are better un- 
derstood, more uniform and better results, may confidently be looked 
for. 



ARTIFICIAL ABRASIVES. 133 

The smaller wheels and points, made for dentists' use, were 
found to cut porcelain much faster than wheels of corundum and 
shellac of the corresponding sizes and grit, and to wear away more 
slowly than the latter. When used dry, they cut faster than dry 
corundum wheels, and do not glaze so readily as these. This qual- 
ity makes their use cleanly for the operator. 

The results of these practical trials may fairly be summarized in 
the statements, that the new material possesses remarkable proper- 
ties as an abrasive, being the first artificial substance, thus far pro- 
duced, which compares favorably with bort in hardness, and which 
is capable of being used as a substitute for it; that, when its pecul- 
iarities are better understood, it should be capable of yielding 
cutting wheels of high efficiency, to take the place of abrasives in 
common use; and that it should find general application in the arts, 
wherever its price is not prohibitory." 



INDEX. 



Abrasives, Natural 119-125 

, Artificial 126-133 

Acbeson, E. G 127 

Actinolite 43 

Acworth 43 

Adams, Frank 15 

Adams, J. H., Cited 116 

Adamantine, Definition 33 

Adairsville 38 

Alabama, Bauxite of ; 38 

Algonkian, Limitations of 69 

Aleck Mountains 97 

Aluminum, Anbydrous oxides of 37-41 

Antbophyllite 43 

Amity, N. Y 16 

Amorpbous, Definition 37 

Apatite 57 

Arcbaean, Cbaracteristics of 68 

Arfvedsonite 44 

Arkansas, Bauxite of 38, 39 

Asbestus 44 

*' Asbestus Rock" 82 

Asbbury, Capt 86 

Asbbury, F. R., Property of 97 

Asterism, Definition of 32 

Auge 40 

Ball Ground 101 

Bauxite 38 

, Analyses of Georgia 39 

Bayley, W. S 15 

Bean, T. S Preface, 97, 98 

Beavett's Mine, Location and Description 87 

Bell Creek Mine, Location and Description 84 

Blackwell, S. J., Property of 101 

Blake, W. P., Cited 116 

Blue Hill, Pa 17 

" Blue Soapstone " 92 

Bournon 46 

Branner, J. C 40 

Brasstown Creek, Corundum Properties of 91 

Breedlove, George 106 

Brownsville, Corundum Properties in Vicinity 

of 104 

Brusb, G. J 16 

Buck Creek, N. C 88 

Buhrstones, witb Statistics 121, 122 

Bull Mount, Va 17 

Burgess, Canada 15 



Burke County, N. C 47 

By on 24 

Cain, Cbarles, Property of 96 

Campbell, J. L., Cited 67 

Canada, Report of Geol. Sur., quoted 15 

Carborundum, Process of Manufacture, etc.127-133 

Caron 34 

Carroll County, Corundum Properties of... 104, 105 

Cartersville Fault 60, 62, 65, 66, 68 

Cbalcedony , ., 37 

Cbatard, T. M 44, 55 

, Analysis by 99 

, Cited ....54, 116 

, Quoted 82,83, 107 

Cberokee County, Corundum Properties of 101 

Cbester, Mass 14, 15, 29, 38, 42, 46 

Cblorites, Defined 49 

, Described 52, 53 

, Differentiation of 52, 53 

Cblorite Scbist, Analysis of 100 

Cbloritoid 52 

CbrOmite 42 

Cbrysolite 45 

— , Rock Analysis of 81 

, Description of 82 



Clay County, N. C 76 

Clintonites, Defined 49 

, Described 52 



Cobb County, Corundum Properties of 101 

Collins, E. R 20 

Cook, Capt. J. R 93 

Cooke, J. P., Cited 116 

Coosa Valley, Bauxite Deposits of 38, 39 

Cortlandt Townsbip, N. Y 16 

Corundophilite 52, 53 

Corundum, American Literature on 116-118 

, Analyses of 30, 103 

, Area Covered by Field Work 73 

• , Cbemical Composition of 29 

, Cleaner ill 

, Cleaner Illustrated 112 

, Cobesion 32 

— , Crystal Forms and Structure 32 

, Defined 23 

, Derivation of Word 23 

, Description of Sand-Corundum.26, 27 

, " " Block-Corundum... 27 

— , " " Crystal-Corundum. 27 



INDEX. 



Corundum, Distribution in Georgia 73-108 

Early Explorers of 14 

Early History of 9-11 

Geological Relations of Formations 74 

History of its Mining 109 

History in North America 13, 14 

History in the Eastern Hemis- 
phere 9-11 

Knowledge of, disseminated hy 14 

Observations on occurrences noted. 107 

Occurrence in Canada 15 

" Massachusetts 16 

" "Connecticut 16 

" " New York 16 

" "New Jersey 16 

" " Maryland 17 

" "Pennsylvania 17 

" " Virginia 17, 18 

" " North Carolina 18 

" Georgia 18, 19 

" " South Carolina 19 

" " Alabama 19 

" " Montana 20 

" " Colorado 20, 21 

" "California 21 

Optical Properties of 33 

Origin of Georgia Deposits 106-108 

Position of Formations 73, 74 

Preparation and Manufacture 

of 110-112 

Specific Gravity of 33 

Statistics of 113 

Types of Veins 75, 76 

Varieties 23 

Varieties Found in Georgia 76 

Walls of Veins 75 

Washing Machine 110 

Washing Machine Illustrated Ill 

Corundum Hill, N. C 37, 38, 41, 48, 49, 53, 55 

Crowder's Mountain, N. C 57 

" Crushed Steel " 126 

Cryptocrystalline, Definition of 37 

Crystalline Belt, Age of 67-69 

— — , Classes of Rocks 62 

, Drainage of 61 

, Introduction to Geology of... 58 

, Structure, Physiography and 

Evolution 61-67 

, Structural Features Noted.65-67 

, Surface Area 60 

, Topography of 60, 61 

Cullakenee Mine, N. C 47, 55 

Culsageeite 54 

Dana, E. S 15, 16, 21, 39, 50 

, Cited 116 

, Quoted 12, 13, 45 

Damourite 50 



.37 



Dawson County, Corundum of 

Deville 

Diaphaneity, Definition of 

Diaspore . 

Dickson, John, Cited 

Douglas County, Corundum Properties of 

Dudleyville, Ala 37, 42. 

Dudleyite , 

Dykes 

Ebelmen 

Egleston, Thomas, Quoted 

Emerson, W. H 

, Analysis by 81, 89, 

Emery, Defined 

, History of 28, 

, Nomenclature 



Enota Mountain, Height of. 

Enstatite 

Ephesite 

Elder, G. B., Property of 

Elder, John, Property of 

Eldorado Bar, Montana 

Euphyllite 

Falls of the Yantic, Conn.... 

Fannin County 

Feil 



34 
34 
38 
116 
104 
,55 
55 
72 
34 
21 
98 
103 
24 
29 
22 
61 
42 
51 
97 
97 
20 
51 
47 
96 
34 

Feldspars, with Table 46 

Fibrolite 47 

Foote, G. B 20 

Forces, Constructive and Destructive 60, 61 

Forsyth County, Corundum Properties of..l00, 101 

Franklin, N. J 16 

Friedel 34 

Fremy 34 

Gannett, Henry, Cited 116 

Garland, Lucius 86 

Gasteropod Fossil (?) 62 

Gaudin 34 

Genth, F. A 38,44, 48, 49, 50, 51, 54, 55 

, Cited 40, 89, 117 

, Quoted 18, 108 

Genthite 42, 56 

Georgia, Formations of 70 

, Map of 58-60 

Gibbsite 41 

Gibson, J. N„ Property of 90 

Gilmer County 96 

Goldschmidt, Table 45 

Graves Mountain 57 

Greenwood, Me 15 

Grindstones, with Statistics 122, 123 

Groth 47 

Gumuch-dagh 41, 42, 51, 52 

Habersham County 63, 73 

.Corundum Properties of.96, 98 



Hall County, Corundum Properties of 98-100 

Hampden Emery Co 77 



INDEX. 



Hamilton Mine 94 

— , Location and Description 91 

Hardness, Method of determining 33 

Hauy 23 

Hawkins, J. W 38 

Hayes, C. W., Cited 38, 40, 42 

Heard County, Corundum Properties of 105 

Hematite 42 

Henderson, Quoted 121,124 

Hiawassee 87 

— ■ , Corundum Properties near 90 

Hicks Asbestus Mine, Location and Descrip- 
tion 83, 84 

Hiddenite 45 

Hill, R. C 20 

Hog Creek Mine 42,47,48,56, 76 

, Location and Description. ..88, 89 

Holo-crystalline Area, Age of Rocks of 71 

, Formations of 63, 64 

, Geology of '. 71, 72 

-, Prevailing type of 

rocks 71 

, Rocks and Structure 

of 63, 64 

, Type of Rocks of 71 

Holo-crystalline Rocks, Defined 62 

Hunt, T. S., Cited 40, 117 

Hunter, C. L., Cited 117 

Hyalite 37 

Hyatt, W. H 105 

Hydrargillite 41 

Ilmenite 42 

Infusorial Earth, with Statistics 119, 120 

Jackson, C. T., Cited 14,15, 29 

Jacksonville, Ala 38 

Jefferisite 54 

Jencks, C. W 14,48, 77 

, Cited 117 

Julien, A. A., Cited 107, 117 

Kimsey, E., Property of 97 

Kerr, W. C 54 

, Cited 117 

Koenig, G. A., Analysis by 100 

Kokscharoffite 44 

Kyanite 47 

Lamb, J. A 85 

Laurel Creek Mine. ...19, 27, 38, 43, 48, 50, 54, 57, 76, 

92, 109 

, Geology of 80-83 

, History of 77-78 

, Location and General Fea- 
tures of .. 78-80 

, Sketch Map of 79 

, Types of Rocks of 80 

Laurens County, S. C 51 

Lazulite 57 

Lea, Dr. Isaac 17, 48, 51 

Lesleyite 51 



Lisle, Rome de 

Litchfield, Conn 16 

Little, George, Cited 

Lucas, H. S 14, 15, 19, 27, 55 

"Lucas Mine " 

Lucasite 

Lumpkin County 

, Corundum Properties in 

Lyons, A. J 97 

Maconite 

Magnetite 

Margarite 

, Analysis of 



McCalley, Henry, Cited. 
McCallie, S. W 

, Cited.... 



McConnell, Wm. R 

McCracken, F. E., Property of.. 

Meunier 

Meadows, Jacob W 

Micas, Defined 

, Described 



23 
,47 
67 
77 
78 
55 
63 
96 
98. 
.... 55 

42 

52 

94 

38 

62. 

63 

.19, 88 

97 

34 

104 

49 

51 



.50 



Miller, Dr., Property of 

Mineral Hill, Pa 

Mohs' Scale of Hardness 

Monroe 44, 

Moreno, Major Theodore, Property of 

Muscovite 

Nacoochee Valley Asbestus-plant 

Naxos 11, 13, 29, 30 

Newlin Township, Pa 14, 17 

Newton, Conn 16 

Nicholson Heirs, Property of 

Norwich, Conn 

Oilstones, with Statistics 124, 

Opal 



Oostanaula Shale 

Painter, James 

Painterite 

Paleozoic, Surface Area of the. 

Paragonite 

Paret, T. Dunkin, Cited 

, Quoted... 

Parker, E. W., Cited 



.65, 67 



, Quoted 18, 

Parting Distinguished from Cleavage 

Paulding County,Corundun Properties of. 103, 

Penfield, S. L 

Phlogopite 

Phosphates 

Pickens County 

Pine Mountain 

Plant, Mr 

Pleochroism, Definition of 

Pliny 

Powder Springs 48, 

Prather, W. T., Property of 

Prochlorite 52 



47 

33 

106 

100 

50 

44 

,48 

,55 

,47 

84 

16, 

125 

37 

, 70' 

55 

55 

60' 

51 

117 

29 

117 

103 

32 

104 

16 

50 

57 

96 

78 

18 

33 

44 

104 

103 

53 



INDEX. 



^Prospectors, Hints to 114 

Pumice 119 

Quartz 37 

Raborg, W. A., Cited 117 

Rabun County 73 

— , Corundum properties of 76-86 

Rand, T. D 17 

Raymond, R. W., Cited 117 

Reeves, Henry, Property of 102 

Robinson, Mr. , of Young Harris 95 

Rock Run, Ala 39 

Rockdale, Pa 17 

Rogers, Elias 101 

Rome, Ga 39 

Sapphire, Description of 25 

, Definition of 23 

.Howtoselect 26 

——.Jewellers' Classification of 24 

.Nomenclature of 22 

, Star Sapphires 25 

Sapphire Valley Company 103 

Schist, Paragonite 51 

Seal, T. S., Cited 41, 117 

Semi-Crystalline Area, Boundaries of 63 

, Rocks and their Struc- 
ture 63 

, Principal Rocks of 62 

Semi-Crystalline, Defined 62 

Serpentine 56 

Shepard, C. U ". 14,15, 18 

, Cited 44, 117 

Shooting Creek, N. C 55 

Silicates, Anhydrous 42-49 

— — , Extent of Basic Magnesian 63, 64 

— , Hydrous 49-55 

, Nature of Basic Magnesian 72 

■Silicon, Oxides of 37 

Sillem, Cited 37 

Silliman 47, 52 

•, Cited 118 

Skeena Creek, N. C 29 

Smaragdite 44 

Smith, Rev. C. D 14,19 

, Cited 118 

, Quoted 18 

Smith, Eugene A., Quoted 19 

Smith, J. Lawrence... 11, 14, 20, 28, 36, 42, 46, 52, 104 

, Analyses by 30 

, Cited 41, 51, 118 

.Quoted 12, 38 

Soapstone 56 

Soapstone Mountain 86 

Southern France, Bauxite of 39 

, Occurrence of Bauxite, with 

Corundum in 40 

Spencer, J. W., Cited 38, 40, 41, 59, 67, 121 

.Quoted 39 

Spinel, Ruby Spinel, Picotite and Hercynite... 41 



Staurolite 49 

Steatite 56 

Stevens, J. H., Property of 95 

Stone Mine, Location and Description of 95 

Stroud, James, Property of 97 

Streeter, Edwin W., Cited. 10,24 

Sussex County, N. J...<. 16 

Talc, Varieties Defined 56 

Tallulah Gorge 61, 63 

Tate Marble Quarries, Basic Intrusions in 63 

Tatum, Property of 97 

Thompson 19, 77 

The New York Corundum and Mining Co 95 

The Sapphire and Ruby Company of Mon- 
tana, Limited 20 

Thulite 46 

Titanite 42 

Towns County, Corundum Properties in 87-91 

Tourmaline 48 

Track ROck Mine 91, 95,109 

— , Bowlder near Fig. 1, 14 

— : , Description of 92-95 

, Source of Name 13 

-, Tunnel Section ....93-94 



Trautwine, J. C , 118 

Tremolite 43 

Tripoli 120, 121 

Trotter, William, Property of 97 

Tschermak, Table by 45 

Tuggle, Jr., Mr., Property of 101 

Turner, W. B., Property of 102 

Tyson 17 

Union County, Corundum Properties in 92-95 

Unionite 47 

Unionville, Pa 17, 38, 46, 47, 48, 51 

VanHise.C. R., Quoted 68 

Vermiculite, Defined 53-55 

, Described 53-55 

, Means of Differentiating 53-54 

Vernon, N. J 16 

Villa Rica 104 

Vitreous, Defined 33 

Wadsworth, M. E., Cited 118 

Walcott, C. D 62 

Walton County, Corundum Properties of 106 

Warwick, N. Y 16 

Washington, Conn 47 

West, E. P., Property of 97 

Westmoreland, Property of 101, 102 

Whatley, E. T 97 

Whetstones, with statistics 124, 125 

White Hall, Md 17 

Winston, Mrs. N. H., Property of 105 

Willcox, Col. Joseph 42, 55 

Cited 118 



Willcoxite 55 

Williams, G. H 16,32, 41 

. Cited 118 



Worley, Tillman, Property of 97 

Worthy, E. P., Property of 105 

Zoisite 46 

, of Hog Creek, with Analysis 89 



LB 'I 



Kk 



